Update deprecated routes in irker integration

Hi !

What does this MR do?

For some reason, according to #28848 (closed) , "deprecated" routes redirects will be removed from gitlab. This is a very annoying breaking changes because what the release notes state are

Regular usage of GitLab will not be impacted by this change. However bookmarks or scripting created over a year ago, utilizing an affected path, will need to be updated to utilize the new path.

does not take into account that hundreds of commit messages contain full URLs to issues they are solving, but whatever. /tableflip

We (Inkscape) have spent hours to update links on our website and in the code (which was also linking to issues in the "old" format)

Anyway, enough ranting for now, one thing we could not fix on our end was the focus of this MR : we use irker and irker uses "old-format" URLs, and this patch attempts to fix this. ( inkscape/inbox#2867 (comment 347954523) )

Screenshots

09:16 < irker087> [inkscape] Thomas Holder pushed 1 new commit to master: https://gitlab.com/inkscape/inkscape/compare/a41a1eac...5dd97498
09:42 < irker087> [inkscape] Thomas Holder pushed 1 new commit to master: https://gitlab.com/inkscape/inkscape/compare/5dd97498...89b7b8b0
13:44 < irker557> [inkscape] Marc Jeanmougin pushed 1 new commit to 1.0.x: https://gitlab.com/inkscape/inkscape/compare/7cf01540...da27a4f9
13:44 < irker557> [inkscape] Marc Jeanmougin has created a new branch cherry-pick-da27a4f9: https://gitlab.com/inkscape/inkscape/branches
13:44 < irker557> [inkscape] Marc Jeanmougin pushed 1 new commit to cherry-pick-da27a4f9: https://gitlab.com/inkscape/inkscape/compare/89b7b8b0...c0e8ebc4
13:45 < irker557> [inkscape] Marc Jeanmougin pushed 1 new commit to master: https://gitlab.com/inkscape/inkscape/compare/89b7b8b0...c0e8ebc4
13:45 < irker557> [inkscape] Marc Jeanmougin has deleted the branch cherry-pick-da27a4f9
13:57 < irker557> [inkscape] Marc Jeanmougin pushed 6 new commits to master: https://gitlab.com/inkscape/inkscape/compare/c0e8ebc4...0cb5f175
16:04 < irker557> [inkscape] Link Mauve pushed 1 new commit to master: https://gitlab.com/inkscape/inkscape/compare/0cb5f175...dc0a27e6

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

What additional test coverage or changes to tests will be needed?

None

Will it require cross-browser testing?

No

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

N/A