fix workflow

.gitea/workflows/build.yml

@@ -5,6 +5,9 @@ on:
     branches: [main]
     tags: ["v*"]
 
+env:
+  REGISTRY: git.thiede-brauer.de
+
 jobs:
   build-and-push:
     runs-on: ubuntu-latest
@@ -13,18 +16,11 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Bei der Registry anmelden
-        run: echo "${{ secrets.GITHUB_TOKEN }}" | docker login ${{ github.server_url }} -u ${{ github.actor }} --password-stdin
-        env:
-          # Bei Gitea/Forgejo zeigt github.server_url auf die eigene Instanz,
-          # z.B. https://git.meinefirma.de
-          DUMMY: ""
+        run: echo "${{ secrets.GITHUB_TOKEN }}" | docker login ${{ env.REGISTRY }} -u ${{ github.actor }} --password-stdin
 
       - name: Image-Namen bestimmen
         id: vars
-        run: |
-          REGISTRY_HOST=$(echo "${{ github.server_url }}" | sed -E 's#https?://##')
-          IMAGE="$REGISTRY_HOST/${{ github.repository }}"
-          echo "image=$IMAGE" >> "$GITHUB_OUTPUT"
+        run: echo "image=${{ env.REGISTRY }}/${{ github.repository }}" >> "$GITHUB_OUTPUT"
 
       - name: Image bauen
         run: docker build -t ${{ steps.vars.outputs.image }}:latest -t ${{ steps.vars.outputs.image }}:${{ github.sha }} .
@@ -32,4 +28,4 @@ jobs:
       - name: Image pushen
         run: |
           docker push ${{ steps.vars.outputs.image }}:latest
-          docker push ${{ steps.vars.outputs.image }}:${{ github.sha }}
+          docker push ${{ steps.vars.outputs.image }}:${{ github.sha }}