Allow periods in versions

.github/workflows/main.yml

@@ -49,7 +49,7 @@ jobs:
         id: stable-version
         if: ${{ github.event_name == 'release' }}
         run: |
-          if ! [[ "${{ github.event.release.tag_name }}" =~ ^[0-9]+\.[0-9]+\.[0-9]+(-[a-zA-Z].*)?$ ]]; then
+          if ! [[ "${{ github.event.release.tag_name }}" =~ ^[0-9]+\.[0-9]+\.[0-9]+(-[a-zA-Z\.].*)?$ ]]; then
               echo "Invalid version: ${{ github.event.release.tag_name }}"
               exit 1
           fi