Add vitest script to package.json

[ibesora]

In #4728 jest was replaced with vitest but the jest script was removed instead of updated. That made npm run test to fail.
This PR fixes it by adding a new entry to package.json called vitest.

Launch Checklist

• Confirm your changes do not include backports from Mapbox projects (unless with compliant license) - if you are not sure about this, please ask!
• Briefly describe the changes in this PR.
• Link to related issues.
• Include before/after visuals or gifs if this PR includes visual changes.
• Write tests for all new functionality.
• Document any changes to public APIs.
• Post benchmark scores.
• Add an entry to CHANGELOG.md under the ## main section.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 91.82%. Comparing base (5ad1709) to head (0cca08f).
Report is 12 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #5219   +/-   ##
=======================================
  Coverage   91.82%   91.82%           
=======================================
  Files         281      281           
  Lines       38807    38807           
  Branches     6766     6766           
=======================================
+ Hits        35635    35636    +1     
+ Misses       3044     3043    -1     
  Partials      128      128           

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[birkskyum]

What suite is executed by this script?

[HarelM]

What did you intended it to run when you added it to the test script?
run-p lint lint-css test-render vitest - see the last invocation.

[birkskyum]

I think the vitest script is supposed to run all the vitest suites, so that would be test-unit test-integration test-build

[ibesora]

I think the vitest script is supposed to run all the vitest suites, so that would be test-unit test-integration test-build

I just did that.
It's true that having a jest test like we had before might not make a lot of sense.