Update GraphQL docs

Ran `gitlab:graphql:schema:dump` as well as
`gitlab:graphql:compile_docs`

doc/api/graphql/reference/gitlab_schema.graphql

@@ -2814,6 +2814,11 @@ type Label {
   """
   descriptionHtml: String
 
+  """
+  Label ID
+  """
+  id: ID!
+
   """
   Text color of the label
   """
@@ -3407,6 +3412,101 @@ type MergeRequestSetAssigneesPayload {
   mergeRequest: MergeRequest
 }
 
+"""
+Autogenerated input type of MergeRequestSetLabels
+"""
+input MergeRequestSetLabelsInput {
+  """
+  A unique identifier for the client performing the mutation.
+  """
+  clientMutationId: String
+
+  """
+  The iid of the merge request to mutate
+  """
+  iid: String!
+
+  """
+  The Label IDs to set. Replaces existing labels by default.
+  """
+  labelIds: [ID!]!
+
+  """
+  Changes the operation mode. Defaults to REPLACE.
+  """
+  operationMode: MutationOperationMode
+
+  """
+  The project the merge request to mutate is in
+  """
+  projectPath: ID!
+}
+
+"""
+Autogenerated return type of MergeRequestSetLabels
+"""
+type MergeRequestSetLabelsPayload {
+  """
+  A unique identifier for the client performing the mutation.
+  """
+  clientMutationId: String
+
+  """
+  Reasons why the mutation failed.
+  """
+  errors: [String!]!
+
+  """
+  The merge request after mutation
+  """
+  mergeRequest: MergeRequest
+}
+
+"""
+Autogenerated input type of MergeRequestSetLocked
+"""
+input MergeRequestSetLockedInput {
+  """
+  A unique identifier for the client performing the mutation.
+  """
+  clientMutationId: String
+
+  """
+  The iid of the merge request to mutate
+  """
+  iid: String!
+
+  """
+  Whether or not to lock the merge request.
+  """
+  locked: Boolean!
+
+  """
+  The project the merge request to mutate is in
+  """
+  projectPath: ID!
+}
+
+"""
+Autogenerated return type of MergeRequestSetLocked
+"""
+type MergeRequestSetLockedPayload {
+  """
+  A unique identifier for the client performing the mutation.
+  """
+  clientMutationId: String
+
+  """
+  Reasons why the mutation failed.
+  """
+  errors: [String!]!
+
+  """
+  The merge request after mutation
+  """
+  mergeRequest: MergeRequest
+}
+
 """
 Autogenerated input type of MergeRequestSetMilestone
 """
@@ -3452,6 +3552,51 @@ type MergeRequestSetMilestonePayload {
   mergeRequest: MergeRequest
 }
 
+"""
+Autogenerated input type of MergeRequestSetSubscription
+"""
+input MergeRequestSetSubscriptionInput {
+  """
+  A unique identifier for the client performing the mutation.
+  """
+  clientMutationId: String
+
+  """
+  The iid of the merge request to mutate
+  """
+  iid: String!
+
+  """
+  The project the merge request to mutate is in
+  """
+  projectPath: ID!
+
+  """
+  The desired state of the subscription
+  """
+  subscribedState: Boolean!
+}
+
+"""
+Autogenerated return type of MergeRequestSetSubscription
+"""
+type MergeRequestSetSubscriptionPayload {
+  """
+  A unique identifier for the client performing the mutation.
+  """
+  clientMutationId: String
+
+  """
+  Reasons why the mutation failed.
+  """
+  errors: [String!]!
+
+  """
+  The merge request after mutation
+  """
+  mergeRequest: MergeRequest
+}
+
 """
 Autogenerated input type of MergeRequestSetWip
 """
@@ -3588,7 +3733,10 @@ type Mutation {
   epicSetSubscription(input: EpicSetSubscriptionInput!): EpicSetSubscriptionPayload
   epicTreeReorder(input: EpicTreeReorderInput!): EpicTreeReorderPayload
   mergeRequestSetAssignees(input: MergeRequestSetAssigneesInput!): MergeRequestSetAssigneesPayload
+  mergeRequestSetLabels(input: MergeRequestSetLabelsInput!): MergeRequestSetLabelsPayload
+  mergeRequestSetLocked(input: MergeRequestSetLockedInput!): MergeRequestSetLockedPayload
   mergeRequestSetMilestone(input: MergeRequestSetMilestoneInput!): MergeRequestSetMilestonePayload
+  mergeRequestSetSubscription(input: MergeRequestSetSubscriptionInput!): MergeRequestSetSubscriptionPayload
   mergeRequestSetWip(input: MergeRequestSetWipInput!): MergeRequestSetWipPayload
   removeAwardEmoji(input: RemoveAwardEmojiInput!): RemoveAwardEmojiPayload
   todoMarkDone(input: TodoMarkDoneInput!): TodoMarkDonePayload

doc/api/graphql/reference/index.md

@@ -410,6 +410,7 @@ The API can be explored interactively using the [GraphiQL IDE](../index.md#graph
 
 | Name  | Type  | Description |
 | ---   |  ---- | ----------  |
+| `id` | ID! | Label ID |
 | `description` | String | Description of the label (markdown rendered as HTML for caching) |
 | `descriptionHtml` | String | The GitLab Flavored Markdown rendering of `description` |
 | `title` | String! | Content of the label |
@@ -491,6 +492,22 @@ The API can be explored interactively using the [GraphiQL IDE](../index.md#graph
 | `errors` | String! => Array | Reasons why the mutation failed. |
 | `mergeRequest` | MergeRequest | The merge request after mutation |
 
+### MergeRequestSetLabelsPayload
+
+| Name  | Type  | Description |
+| ---   |  ---- | ----------  |
+| `clientMutationId` | String | A unique identifier for the client performing the mutation. |
+| `errors` | String! => Array | Reasons why the mutation failed. |
+| `mergeRequest` | MergeRequest | The merge request after mutation |
+
+### MergeRequestSetLockedPayload
+
+| Name  | Type  | Description |
+| ---   |  ---- | ----------  |
+| `clientMutationId` | String | A unique identifier for the client performing the mutation. |
+| `errors` | String! => Array | Reasons why the mutation failed. |
+| `mergeRequest` | MergeRequest | The merge request after mutation |
+
 ### MergeRequestSetMilestonePayload
 
 | Name  | Type  | Description |
@@ -499,6 +516,14 @@ The API can be explored interactively using the [GraphiQL IDE](../index.md#graph
 | `errors` | String! => Array | Reasons why the mutation failed. |
 | `mergeRequest` | MergeRequest | The merge request after mutation |
 
+### MergeRequestSetSubscriptionPayload
+
+| Name  | Type  | Description |
+| ---   |  ---- | ----------  |
+| `clientMutationId` | String | A unique identifier for the client performing the mutation. |
+| `errors` | String! => Array | Reasons why the mutation failed. |
+| `mergeRequest` | MergeRequest | The merge request after mutation |
+
 ### MergeRequestSetWipPayload
 
 | Name  | Type  | Description |