ci fixes

.github/workflows/build.yaml

@@ -4,7 +4,11 @@ on:
       image:
         description: "Resulting docker image (tagged with commit SHA)"
         value: ${{ jobs.set_image_name.outputs.image }}
-
+  workflow_dispatch:
+    inputs:
+      tag:
+        type: string
+        description: Image tag
 env:
   # Use docker.io for Docker Hub if empty
   REGISTRY: ghcr.io
@@ -20,8 +24,6 @@ jobs:
     steps:
     - name: Checkout repository
       uses: actions/checkout@v3
-      with:
-        ref: ${{ github.event.pull_request.head.sha }}
 
     # Workaround: https://github.com/docker/build-push-action/issues/461
     - name: Setup Docker buildx
@@ -56,8 +58,8 @@ jobs:
       uses: docker/build-push-action@ac9327eae2b366085ac7f6a2d02df8aa8ead720a
       with:
         context: .
-        push: true
-        tags: ${{ steps.meta.outputs.tags }}
+        push: github.event_name != 'pull_request'
+        tags: ${{ steps.meta.outputs.tags || github.event.inputs.tag }}
         labels: ${{ steps.meta.outputs.labels }}
         cache-from: type=gha
         cache-to: type=gha,mode=max

.github/workflows/checks.yaml

@@ -1,9 +1,8 @@
 name: Checks
 
 on:
-  pull_request_target:
-    branches:
-      - "main"
+  pull_request:
+  push:
 
 defaults:
   run:
@@ -29,8 +28,6 @@ jobs:
     steps:
       - name: "Checkout"
         uses: actions/checkout@v3
-        with:
-          ref: ${{ github.event.pull_request.head.sha }}
       - run: "make lint/${{ matrix.linter }}"
 
   test: