CI: build container when the version is a clean git tag 1

.forgejo/workflows/build.yaml

@@ -43,12 +43,10 @@ jobs:
 
       - name: Check if the container should be built
         id: builder
-        env:
-          builder: ${{ inputs.build || !contains(steps.version.output.version, '-') }}
-        run: echo $builder
+        run: echo "run=${{ inputs.build || !contains(steps.version.output.version, '-') }}" >> $GITHUB_OUTPUT
 
       - name: Build container
-        if: ${{ steps.builder.builder }}
+        if: ${{ steps.builder.output.run }}
         uses: actions/buildah-build@v1
         with:
           image: treetrail-frontend
@@ -59,13 +57,13 @@ jobs:
             ./Containerfile
 
       - name: Workaround for bug of podman-login
-        if: ${{ steps.builder.builder }}
+        if: ${{ steps.builder.output.run }}
         run: |
           mkdir -p $HOME/.docker
           echo "{ \"auths\": {} }" > $HOME/.docker/config.json
 
       - name: Log in to container registry (with another workaround)
-        if: ${{ steps.builder.builder }}
+        if: ${{ steps.builder.output.run }}
         uses: actions/podman-login@v1
         with:
           registry: ${{ vars.REGISTRY }}
@@ -74,7 +72,7 @@ jobs:
           auth_file_path: /tmp/auth.json
 
       - uses: actions/push-to-registry@v2
-        if: ${{ steps.builder.builder }}
+        if: ${{ steps.builder.output.run }}
         with:
           registry: "docker://${{ vars.REGISTRY }}"
           image: treetrail-frontend