ci: run on examples & build.rs

Author: backwardspy

.github/workflows/build.yml

@@ -3,13 +3,14 @@ name: build
 on:
   workflow_dispatch:
   push:
-    paths:
+    paths: &paths
       - "src/**"
+      - "examples/**"
+      - "build.rs"
       - "Cargo.toml"
   pull_request:
     paths:
-      - "src/**"
-      - "Cargo.toml"
+      - *paths
 
 jobs:
   compile: