fix: lowercase GHCR image tags for Docker push

Author: echobt

.github/workflows/ci.yml

@@ -119,6 +119,10 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
+      - name: Lowercase repo name
+        id: lower
+        run: echo "repo=$(echo '${{ github.repository }}' | tr '[:upper:]' '[:lower:]')" >> "$GITHUB_OUTPUT"
+
       - name: Login to GHCR
         uses: docker/login-action@v3
         with:
@@ -132,5 +136,5 @@ jobs:
           context: .
           push: true
           tags: |
-            ghcr.io/${{ github.repository }}:latest
-            ghcr.io/${{ github.repository }}:${{ github.sha }}
+            ghcr.io/${{ steps.lower.outputs.repo }}:latest
+            ghcr.io/${{ steps.lower.outputs.repo }}:${{ github.sha }}