Merge pull request #9999 from nextcloud/chore/qa_pr_target

qa: run on pull_request_target, to enable running on fork PRs

.github/workflows/qa.yml

@@ -1,20 +1,18 @@
 name: "QA"
 
 on:
-    pull_request:
+    pull_request_target:
         branches: [ master, stable-* ]
 
 jobs:
     qa:
         runs-on: ubuntu-latest
         steps:
-            -   name: Check if secrets are available
-                run: echo "::set-output name=ok::${{ secrets.KS_PASS != '' }}"
-                id: check-secrets
             -   uses: actions/checkout@v3
-                if: ${{ steps.check-secrets.outputs.ok == 'true' }}
+                with:
+                    repository: ${{ github.event.pull_request.head.repo.full_name }}
+                    ref: $GITHUB_HEAD_REF
             -   name: set up JDK 11
-                if: ${{ steps.check-secrets.outputs.ok == 'true' }}
                 uses: actions/setup-java@v2
                 with:
                     distribution: "temurin"
@@ -24,7 +22,6 @@ jobs:
                     source ndk.env
                     /usr/local/lib/android/sdk/tools/bin/sdkmanager "ndk;${NDK_VERSION}" "cmake;${CMAKE_VERSION}"
             -   name: Build QA
-                if: ${{ steps.check-secrets.outputs.ok == 'true' }}
                 env:
                     KS_PASS: ${{ secrets.KS_PASS }}
                     KEY_PASS: ${{ secrets.KEY_PASS }}