Updates default custom flavor builder tag to beta

Changes the default tag used when building custom MegaLinter flavors from 'alpha' to 'beta'.

This ensures that users who do not explicitly specify a tag will receive the 'beta' version by default, providing a more stable and tested experience compared to 'alpha'.

Author: nvuillam

mega-linter-runner/generators/mega-linter-custom-flavor/templates/megalinter-custom-flavor-builder.yml

@@ -68,7 +68,7 @@ jobs:
       - name: Build MegaLinter Custom Flavor
         uses: oxsecurity/megalinter/flavors/custom-builder@main
         with:
-          megalinter-custom-flavor-builder-tag: ${{ github.event_name == 'release' && github.event.release.tag_name || 'alpha' }}
+          megalinter-custom-flavor-builder-tag: ${{ github.event_name == 'release' && github.event.release.tag_name || 'beta' }}
           is-latest: ${{ github.event_name == 'release' && 'true' || 'false' }}
           upload-to-ghcr: "true"
           upload-to-dockerhub: ${{ secrets.DOCKERHUB_USERNAME != '' && secrets.DOCKERHUB_PASSWORD != '' && 'true' || 'false' }}