Add media-query color mode Sass test

[julien-deramond]

Description

Related to #38322, this PR suggests adding an automatic test to build Bootstrap with $color-mode: "media-query" enabled since we released a version with errors for this use case.

IDK if a kind of "assert true" is mandatory here.

/cc @mdo and @romaricpascal for thoughts

Motivation & Context

Not releasing again a version with errors with $color-mode: "media-query".

Type of changes

• Enhancement (non-breaking change which adds functionality)

Checklist

• I have read the contributing guidelines
• My code follows the code style of the project (using npm run lint)
• My change introduces changes to the documentation
• (N/A) I have updated the documentation accordingly
• I have added tests to cover my changes
• All new and existing tests passed

Related issues

#38322

[mdo]

Looks great! I've opened a PR to address the selector itself here at #38328.

[julien-deramond]

Rebasing it after #38328.
Should be green now 🙏
If so