Add workflow for gh-pages branch (#1423)

Signed-off-by: CaptainIRS <36656347+CaptainIRS@users.noreply.github.com>

Author: CaptainIRS

.github/workflows/pr.yml

@@ -2,14 +2,18 @@ name: CI (PR)
 
 on:
   pull_request:
-    branches: [ "main" ]
+    branches:
+      - "main"
+      - "gh-pages"
 
 jobs:
   dci-lint:
     uses: ./.github/workflows/dci.yml
   unit-tests:
+    if: ${{ github.base_ref == 'main' }}
     uses: ./.github/workflows/unit-tests.yml
     needs: dci-lint
   integration-tests:
+    if: ${{ github.base_ref == 'main' }}
     uses: ./.github/workflows/integration-tests.yml
     needs: unit-tests