chore: make lint happy

.github/workflows/gomod2nix.yml

@@ -1,6 +1,8 @@
 name: 自动更新 nix 依赖
 on:
   push:
+    branches:
+      - master
     paths:
       - 'go.mod'
       - 'go.sum'
@@ -23,6 +25,7 @@ jobs:
       - name: Check out code into the Go module directory
         uses: actions/checkout@master
         with:
+          ref: master
           fetch-depth: 0
 
       - name: gomod2nix update