LoopVectorization small grant completion

[mxpoch]

Checklist

• Appropriate tests were added
• Any code changes were done in a way that does not break public API
• All documentation related to code changes were updated
• The new code follows the
  contributor guidelines, in particular the SciML Style Guide and
  COLPRAC.
• Any new documentation only uses public API

Additional context

Moved the LoopVectorization small grant project into the completed projects section.

Updated LoopVectorization and VectorizationBase for compatibility with Julia 1.12. The main work was completed in PR1 and PR2.