ci: run pipeline on main

this will ensure the container can always build and keep caches ready for release. push should only happen on tag triggers

It also removes some files from the PR trigger that should never break the build, and would just invalidate cache.

.github/workflows/docker-release.yml

@@ -4,14 +4,14 @@ on:
   push:
     tags:
       - '*Release*'
+    branches:
+      - master
   pull_request:
     branches:
       - master
     paths:
       - '.github/workflows/docker-release.yml'
       - 'CMakeLists.txt'
-      - 'LICENSE'
-      - 'README.md'
       - 'Dockerfile'
       - 'servatrice/**'
       - 'common/**'
@@ -52,7 +52,7 @@ jobs:
         uses: docker/setup-buildx-action@v3
 
       - name: Login to GitHub Container Registry
-        if: github.event_name != 'pull_request'
+        if: github.ref_type == 'tag'
         uses: docker/login-action@v3
         with:
           registry: ghcr.io
@@ -64,7 +64,7 @@ jobs:
         with:
           context: .
           platforms: linux/amd64,linux/arm64
-          push: ${{ github.event_name != 'pull_request' }}
+          push: ${{ github.ref_type == 'tag' }}
           tags: ${{ steps.metadata.outputs.tags }}
           labels: ${{ steps.metadata.outputs.labels }}
           cache-from: type=gha