Add sub-nav for Project Integration Services edit page

What does this MR do?

Services' edit page under Project -> Settings -> Integration doesn't show sub-nav, this MR adds missing sub-nav.

Why was this MR needed?

Since we moved project settings from dropdown menu to nav tab, sub-nav is not shown in services' edit page, this MR fixes the same.

Screenshots

Before

After

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• [ ] Documentation created/updated
• [ ] API support added
• Tests
  • [ ] Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Closes #31174 (closed)

marked the checklist item Conform by the merge request performance guides as completed

marked the checklist item Conform by the style guides as completed

marked the checklist item Branch has no merge conflicts with master (if it does - rebase it please) as completed

marked the checklist item Squashed related commits together as completed

added 1 commit

• b7194ba8 - [ci skip] Add changelog entry

Compare with previous version

@alfredo1 it is ready for review, please note that Pipeline is passed for actual changes, I've skipped running pipeline for Changelog entry.

assigned to @alfredo1

marked the checklist item Changelog entry added, if necessary as completed

marked the checklist item All builds are passing as completed

resolved all discussions

approved this merge request

@kushalpandya LGTM Thanks!

merged

mentioned in commit 5d76a6e6

changed milestone to %9.1

mentioned in issue #31285 (closed)

Picked into 9-1-stable, will go into 9.1.1.

mentioned in commit 4aec52ea

mentioned in issue #30864 (closed)