actions: run build on push with path filter

Author: sophec

.github/workflows/cmake.yml

@@ -2,9 +2,13 @@ name: CMake
 
 on:
   push:
-    branches: [ main ]
-  pull_request:
-    branches: [ main ]
+    paths:
+      - '**.h'
+      - '**.cpp'
+      - '**.c'
+      - '**.cmake'
+      - '**/CMakeLists.txt'
+      - '.github/workflows/**'
 
 env:
   # Customize the CMake build type here (Release, Debug, RelWithDebInfo, etc.)