Use Go version from module

Instead of hardcoded version

.github/workflows/gotest.yml

@@ -18,7 +18,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v3
         with:
-          go-version: "1.21"
+          go-version-file: go.mod
 
       - name: Set up dependencies
         run: |