Update parser gem

What does this MR do?

This eliminates the Ruby 2.7.5 warnings:

warning: parser/current is loading parser/ruby27, which recognizes
warning: 2.7.2-compliant syntax, but you are running 2.7.4.
warning: please see https://github.com/whitequark/parser#compatibility-with-ruby-mri.

This adds support for Ruby 2.7.5, 3.1, etc: https://github.com/whitequark/parser/blob/master/CHANGELOG.md

• Full diff: https://my.diffend.io/gems/parser/2.7.2.0/3.1.1.0

Related issues

Checklist

See Definition of done.

For anything in this list which will not be completed, please provide a reason in the MR discussion.

Required

• Merge Request Title and Description are up to date, accurate, and descriptive
• MR targeting the appropriate branch
• MR has a green pipeline on GitLab.com

Expected (please provide an explanation if not completing)

• Test plan indicating conditions for success has been posted and passes
• Documentation created/updated
• Tests added
• Integration tests added to GitLab QA
• Equivalent MR/issue for omnibus-gitlab opened