Remove outdated GitLab version mentions

doc/api/integrations.md

@@ -726,8 +726,6 @@ GET /projects/:id/integrations/github
 
 ## Hangouts Chat
 
-> [Introduced](https://gitlab.com/gitlab-org/gitlab-foss/-/merge_requests/20290) in GitLab 11.2.
-
 Google Workspace team collaboration tool.
 
 ### Create/Edit Hangouts Chat integration
@@ -738,9 +736,6 @@ Set Hangouts Chat integration for a project.
 PUT /projects/:id/integrations/hangouts-chat
 ```
 
-NOTE:
-Specific event parameters (for example, `push_events` flag) were [introduced](https://gitlab.com/gitlab-org/gitlab-foss/-/merge_requests/11435) in GitLab 10.4.
-
 Parameters:
 
 | Parameter | Type | Required | Description |
@@ -832,10 +827,6 @@ GET /projects/:id/integrations/jira
 
 Set Jira integration for a project.
 
-> Starting with GitLab 8.14, `api_url`, `issues_url`, `new_issue_url` and
-> `project_url` are replaced by `url`. If you are using an
-> older version, [follow this documentation](https://gitlab.com/gitlab-org/gitlab/-/blob/8-13-stable-ee/doc/api/services.md#jira).
-
 ```plaintext
 PUT /projects/:id/integrations/jira
 ```
@@ -1198,9 +1189,6 @@ Set Slack integration for a project.
 PUT /projects/:id/integrations/slack
 ```
 
-NOTE:
-Specific event parameters (for example, `push_events` flag and `push_channel`) were [introduced](https://gitlab.com/gitlab-org/gitlab-foss/-/merge_requests/11435) in GitLab 10.4.
-
 Parameters:
 
 | Parameter | Type | Required | Description |
@@ -1308,9 +1296,6 @@ Set Mattermost notifications integration for a project.
 PUT /projects/:id/integrations/mattermost
 ```
 
-NOTE:
-Specific event parameters (for example, `push_events` flag and `push_channel`) were [introduced](https://gitlab.com/gitlab-org/gitlab-foss/-/merge_requests/11435) in GitLab 10.4.
-
 Parameters:
 
 | Parameter | Type | Required | Description |