Hide `/epic` and `/remove_epic` for unsupported issuables

For example, incidents cannot be linked to epics.

ee/lib/ee/gitlab/quick_actions/issue_actions.rb

@@ -12,7 +12,8 @@ module EE
           explanation _('Adds an issue to an epic.')
           types Issue
           condition do
-            quick_action_target.project.group&.feature_available?(:epics) &&
+            quick_action_target.supports_epic? &&
+              quick_action_target.project.group&.feature_available?(:epics) &&
               current_user.can?(:"admin_#{quick_action_target.to_ability_name}", quick_action_target)
           end
           params '<&epic | group&epic | Epic URL>'
@@ -42,6 +43,7 @@ module EE
           types Issue
           condition do
             quick_action_target.persisted? &&
+              quick_action_target.supports_epic? &&
               quick_action_target.project.group&.feature_available?(:epics) &&
               current_user.can?(:"admin_#{quick_action_target.to_ability_name}", quick_action_target)
           end

ee/spec/services/ee/notes/quick_actions_service_spec.rb

@@ -52,6 +52,20 @@ RSpec.describe Notes::QuickActionsService do
         end
       end
 
+      context 'on an incident' do
+        before do
+          issue.update!(issue_type: :incident)
+        end
+
+        it 'leaves the note empty' do
+          expect(execute(note)).to be_empty
+        end
+
+        it 'does not assigns the issue to the epic' do
+          expect { execute(note) }.not_to change { issue.reload.epic }
+        end
+      end
+
       context 'on a merge request' do
         let(:note_mr) { create(:note_on_merge_request, project: project, note: note_text) }
 
@@ -97,6 +111,16 @@ RSpec.describe Notes::QuickActionsService do
         end
       end
 
+      context 'on an incident' do
+        before do
+          issue.update!(issue_type: :incident)
+        end
+
+        it 'leaves the note empty' do
+          expect(execute(note)).to be_empty
+        end
+      end
+
       context 'on a merge request' do
         let(:note_mr) { create(:note_on_merge_request, project: project, note: note_text) }
 

ee/spec/services/quick_actions/interpret_service_spec.rb

@@ -362,6 +362,16 @@ RSpec.describe QuickActions::InterpretService do
               expect(message).to eq("Issue #{issue.to_reference} has already been added to epic #{epic.to_reference}.")
             end
           end
+
+          context 'when issuable does not support epics' do
+            it 'does not assign an incident to an epic' do
+              incident = create(:incident, project: project)
+
+              _, updates = service.execute(content, incident)
+
+              expect(updates).to be_empty
+            end
+          end
         end
 
         context 'when epic does not exist' do
@@ -720,13 +730,18 @@ RSpec.describe QuickActions::InterpretService do
 
     context 'remove_epic command' do
       let(:epic) { create(:epic, group: group) }
-      let(:content) { "/remove_epic #{epic.to_reference(project)}" }
+      let(:content) { "/remove_epic" }
 
       before do
+        stub_licensed_features(epics: true)
         issue.update!(epic: epic)
       end
 
       context 'when epics are disabled' do
+        before do
+          stub_licensed_features(epics: false)
+        end
+
         it 'does not recognize /remove_epic' do
           _, updates = service.execute(content, issue)
 
@@ -745,6 +760,16 @@ RSpec.describe QuickActions::InterpretService do
           expect(updates).to eq(epic: nil)
         end
       end
+
+      context 'when issuable does not support epics' do
+        it 'does not recognize /remove_epic' do
+          incident = create(:incident, project: project, epic: epic)
+
+          _, updates = service.execute(content, incident)
+
+          expect(updates).to be_empty
+        end
+      end
     end
 
     context 'approve command' do