ci: dont use go tool

Author: hikitani

.github/workflows/coverage.yml

@@ -24,7 +24,6 @@ jobs:
       - name: Test
         run: |
           go test -v -cover ./... -coverprofile coverage.out -coverpkg ./...
-          go tool cover -func coverage.out -o coverage.out
 
       - name: Report Coveralls
         uses: coverallsapp/github-action@v2