ruby: Add a new injection for regular expressions (#12533)
# Summary
Hello. This pull request adds a new injection to `injections.scm` for
Ruby language to highlight regular expressions. Thanks.
## Before

## After

Release Notes:
- N/A
Co-authored-by: Marshall Bowers <elliott.codes@gmail.com>
356fcec337Vitaly Slobodin committed on 5/31/2024, 4:02:59 PM· committed by GitHubparent08123a2