ci: fix ghcr build

Author: JakobLichterfeld

.github/workflows/buildx.yml

@@ -55,7 +55,7 @@ jobs:
           repository_owner: ${{ github.repository_owner }}
           repository: ${{ github.repository }}
           github_token: ${{ secrets.GITHUB_TOKEN }}
-          version: ${{ github.ref_name }}
+          version: ${{ github.head_ref || github.ref_name }}
 
   teslamate_merge:
     runs-on: ubuntu-24.04

.github/workflows/ghcr_build.yml

@@ -50,7 +50,7 @@ jobs:
           repository_owner: ${{ github.repository_owner }}
           repository: ${{ github.repository }}
           github_token: ${{ secrets.GITHUB_TOKEN }}
-          version: ${{ github.ref_name }}
+          version: ${{ github.head_ref || github.ref_name }}
           labels: |
             org.opencontainers.image.version=${{ github.ref || github.ref_name }}