1. Fix wrong atomic pkg from go1.19 std sync/atomic to go.uber.org/atomic (#1479)

2. Fix CI buildtest config '>=1.18' to '1.18'，ensure compatibility with go1.18

.github/workflows/buildtest.yaml

@@ -21,7 +21,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v3
         with:
-          go-version: '>=1.18'
+          go-version: '1.18'
 
       - name: Set up gotestfmt
         run: go install github.com/gotesttools/gotestfmt/v2/cmd/gotestfmt@v2.4.1