fix repositry casing

.gitea/actions/build/action.yml

@@ -30,11 +30,18 @@ runs:
         username: ${{ inputs.REGISTRY_USER }}
         password: ${{ inputs.REGISTRY_ACCESS_TOKEN }}
 
+    - name: Set repository variable
+      shell: bash
+      run: |
+        REPOSITORY=$(echo "${{ gitea.repository }}" | tr '[:upper:]' '[:lower:]')
+        echo "REPOSITORY=$REPOSITORY" >> $GITHUB_ENV
+        echo "Repository: $REPOSITORY"
+
     - name: Build and push image
       uses: docker/build-push-action@v6
       with:
         push: true
-        tags: ${{ vars.INSTANCE_URL }}/${{ gitea.repository }}:${{ inputs.tag }}
+        tags: ${{ vars.INSTANCE_URL }}/$REPOSITORY:${{ inputs.tag }}
 
     - name: Set output
       shell: bash