TOOLS-1: Fix build of Docker image

Author: nicolasramy

.github/workflows/build.yml

@@ -28,10 +28,16 @@ jobs:
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
+      - name: Lowercase repository name
+        id: repository_name
+        uses: ASzc/change-string-case-action@v1
+        with:
+          string: ${{ github.repository }}
+
       - name: Build & Push image
         uses: docker/build-push-action@v2
         with:
           context: .
           push: true
           tags: |
-            ghcr.io/${{ github.repository.lower }}:${{ github.base_ref }}
+            ghcr.io/${{ steps.repository_name.outputs.lowercase }}:${{ github.base_ref }}