fix(gitlab): skip on unknown reviewers

[RahulGautamSingh]

Changes

• If unable to find a reviewer, skip instead of failing so we can still add the other reviewers

Context

Please select one of the following:

• This closes an existing Issue, Closes: reviewersFromCodeOwners does not request any users if one user doesn't exist #38622
• This doesn't close an Issue, but I accept the risk that this PR may be closed if maintainers disagree with its opening or implementation

AI assistance disclosure

Did you use AI tools to create any part of this pull request?

Please select one option and, if yes, briefly describe how AI was used (e.g., code, tests, docs) and which tool(s) you used.

• No — I did not use AI for this contribution.
• Yes — minimal assistance (e.g., IDE autocomplete, small code completions, grammar fixes).
• Yes — substantive assistance (AI-generated non‑trivial portions of code, tests, or documentation).
• Yes — other (please describe):

Documentation (please check one with an [x])

• I have updated the documentation, or
• No documentation update is required

How I've tested my work (please select one)

I have verified these changes via:

• Code inspection only, or
• Newly added/modified unit tests, or
• No unit tests, but ran on a real repository, or
• Both unit tests + ran on a real repository

The public repository: https://gitlab.com/rahultesnik/test-codeowners/-/merge_requests/8

[secustor]

I think only printing this once makes sense here

[viceice]

change can be done in separate PR

[viceice]

we should change this to be similar to forgejo and GitHub. so teams need to be prefixed with team:

[RahulGautamSingh]

Won't that break the feature as it's not necessary to use team: prefix in the CODEOWNERS file?

[viceice]

😕 that's disapointing. on github they are prefixed with @org/ in CODEOWNERS 🤔

• https://docs.gitlab.com/user/project/codeowners/reference/#group-eligibility