CI: Only run the CI on pull requests, and on the "main" branch

Previously, the actions were duplicated, due to the fact when developing
we often create feature branches and open pull requests.

This new setup requires us to open pull requests to trigger the CI.

.github/workflows/build.yml

@@ -1,6 +1,6 @@
 name: Build dev environments
 on:
-  push:
+  pull_request:
   schedule:
     - cron: "0 0 * * *" # Run every day at 00:00 UTC.
 

.github/workflows/check_push.yml

@@ -1,6 +1,6 @@
 name: Check branch conformity
 on:
-  push:
+  pull_request:
 
 jobs:
   prevent-fixup-commits:

.github/workflows/ci.yml

@@ -1,8 +1,9 @@
 name: Tests
 on:
   push:
+    branches:
+      - main
   pull_request:
-    branches: [main]
   schedule:
     - cron: "2 0 * * *" # Run every day at 02:00 UTC.
   workflow_dispatch:
@@ -24,7 +25,24 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
+  should-run:
+    runs-on: ubuntu-latest
+    outputs:
+      run-workflow: ${{ steps.check.outputs.run-workflow }}
+    steps:
+      - id: check
+        run: |
+          if [[ "${{ github.event_name }}" == "pull_request" ]]; then
+            echo "run-workflow=true" >> $GITHUB_OUTPUT
+          elif [[ "${{ github.event_name }}" == "push" && "${{ github.ref }}" != "refs/heads/main" ]]; then
+            echo "run-workflow=true" >> $GITHUB_OUTPUT
+          else
+            echo "run-workflow=false" >> $GITHUB_OUTPUT
+          fi
+
   run-lint:
+    needs: should-run
+    if: needs.should-run.outputs.run-workflow == 'true'
     runs-on: ubuntu-latest
     container:
       image: debian:bookworm
@@ -43,6 +61,8 @@ jobs:
   # This is already built daily by the "build.yml" file
   # But we also want to include this in the checks that run on each push.
   build-container-image:
+    needs: should-run
+    if: needs.should-run.outputs.run-workflow == 'true'
     runs-on: ubuntu-24.04
     steps:
       - uses: actions/checkout@v4
@@ -67,6 +87,8 @@ jobs:
           python3 ./install/common/build-image.py
 
   download-tessdata:
+    needs: should-run
+    if: needs.should-run.outputs.run-workflow == 'true'
     name: Download and cache Tesseract data
     runs-on: ubuntu-latest
     steps:
@@ -91,7 +113,10 @@ jobs:
 
   windows:
     runs-on: windows-latest
-    needs: download-tessdata
+    needs:
+      - download-tessdata
+      - should-run
+    if: needs.should-run.outputs.run-workflow == 'true'
     env:
       DUMMY_CONVERSION: 1
     steps:
@@ -121,7 +146,10 @@ jobs:
   macOS:
     name: "macOS (${{ matrix.arch }})"
     runs-on: ${{ matrix.runner }}
-    needs: download-tessdata
+    needs:
+      - download-tessdata
+      - should-run
+    if: needs.should-run.outputs.run-workflow == 'true'
     strategy:
       matrix:
         include:
@@ -149,9 +177,12 @@ jobs:
         run: poetry run make test
 
   build-deb:
+    needs:
+      - should-run
+      - build-container-image
+    if: needs.should-run.outputs.run-workflow == 'true'
     name: "build-deb (${{ matrix.distro }} ${{ matrix.version }})"
     runs-on: ubuntu-latest
-    needs: build-container-image
     strategy:
       matrix:
         include:
@@ -221,7 +252,10 @@ jobs:
   install-deb:
     name: "install-deb (${{ matrix.distro }} ${{ matrix.version }})"
     runs-on: ubuntu-latest
-    needs: build-deb
+    needs: 
+      - build-deb
+      - should-run
+    if: needs.should-run.outputs.run-workflow == 'true'
     strategy:
       matrix:
         include:
@@ -277,7 +311,10 @@ jobs:
   build-install-rpm:
     name: "build-install-rpm (${{ matrix.distro }} ${{matrix.version}})"
     runs-on: ubuntu-latest
-    needs: build-container-image
+    needs:
+      - build-container-image
+      - should-run
+    if: needs.should-run.outputs.run-workflow == 'true'
     strategy:
       matrix:
         distro: ["fedora"]
@@ -343,6 +380,8 @@ jobs:
     needs:
       - build-container-image
       - download-tessdata
+      - should-run
+    if: needs.should-run.outputs.run-workflow == 'true'
     strategy:
       matrix:
         include:

.github/workflows/scan.yml

@@ -1,8 +1,9 @@
 name: Scan latest app and container
 on:
   push:
+    branches:
+      - main
   pull_request:
-    branches: [ main ]
   schedule:
     - cron: '0 0 * * *' # Run every day at 00:00 UTC.
   workflow_dispatch: