Update tests.yml

Author: smlu

.github/workflows/tests.yml

@@ -5,6 +5,7 @@ on:
     branches: [ "master", "develop" ]
   pull_request:
     branches: [ "master", "develop" ]
+  workflow_dispatch:
 
 env:
   # Customize the CMake build type here (Release, Debug, RelWithDebInfo, etc.)