Update Docker build workflow to enforce lowercase repository names

- Modified the Docker build process in docker-build.yml to convert the repository name to lowercase, ensuring consistent image naming conventions.
- This change helps prevent potential issues with case sensitivity in image tags when pushing to the registry.

.gitea/workflows/docker-build.yml

@@ -34,7 +34,8 @@ jobs:
 
       - name: Build and push
         run: |
-          IMAGE="${{ steps.registry.outputs.host }}/${{ github.repository }}"
+          REPO_LOWER=$(echo "${{ github.repository }}" | tr '[:upper:]' '[:lower:]')
+          IMAGE="${{ steps.registry.outputs.host }}/$REPO_LOWER"
           TAG="${{ steps.meta.outputs.tag }}"
           docker build -t "$IMAGE:$TAG" -t "$IMAGE:latest" .
           docker push "$IMAGE:$TAG"