ci: update benchmark.yml

Author: Boshen

.github/workflows/benchmark.yml

@@ -8,19 +8,13 @@ on:
     types:
       - opened
       - synchronize
-    paths:
-      - "src/*.rs"
-      - "Cargo.lock"
   push:
     branches:
       - main
-    paths:
-      - "src/*.rs"
-      - "Cargo.lock"
 
 concurrency:
-  group: ${{ github.workflow }}-${{ github.ref }}
-  cancel-in-progress: true
+  group: ${{ github.workflow }}-${{ github.ref_name }}-${{ github.event.pull_request.number || github.sha }}
+  cancel-in-progress: ${{ github.ref_name != 'main' }}
 
 jobs:
   benchmark: