test(angular): ng15 test infrastructure (#26197)

.github/workflows/actions/test-angular-e2e/action.yml

@@ -37,7 +37,7 @@ runs:
       shell: bash
       working-directory: ./angular/test
     - name: Install Dependencies
-      run: npm install
+      run: npm install --legacy-peer-deps
       shell: bash
       working-directory: ./angular/test/build/${{ inputs.app }}
     - name: Sync Built Changes

.github/workflows/build.yml

@@ -145,7 +145,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        apps: [ng12, ng13, ng14]
+        apps: [ng12, ng13, ng14, ng15]
     needs: [build-angular, build-angular-server]
     runs-on: ubuntu-latest
     steps: