CI: Only run unit tests for pull requests

.github/workflows/rpcs3.yml

@@ -56,6 +56,7 @@ jobs:
       COMPILER: ${{ matrix.compiler }}
       UPLOAD_COMMIT_HASH: ${{ matrix.UPLOAD_COMMIT_HASH }}
       UPLOAD_REPO_FULL_NAME: ${{ matrix.UPLOAD_REPO_FULL_NAME }}
+      RUN_UNIT_TESTS: github.event_name == 'pull_request' && 'ON' || 'OFF'
     steps:
       - name: Checkout repository
         uses: actions/checkout@main
@@ -180,6 +181,7 @@ jobs:
         run: msbuild rpcs3.sln /p:Configuration=Release /v:minimal /p:Platform=x64 /p:PreferredToolArchitecture=x64 /p:CLToolPath=${{ env.CCACHE_BIN_DIR }} /p:UseMultiToolTask=true /p:CustomAfterMicrosoftCommonTargets="${{ github.workspace }}\buildfiles\msvc\ci_only.targets"
 
       - name: Run Unit Tests
+        if: github.event_name == 'pull_request'
         shell: pwsh
         run: build\lib\Release-x64\rpcs3_test.exe