Bump Go version for GH actions

Author: thockin

.github/workflows/apidiff.yaml

@@ -10,7 +10,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v2
         with:
-          go-version: 1.16.x
+          go-version: 1.18.x
       - name: Add GOBIN to PATH
         run: echo "PATH=$(go env GOPATH)/bin:$PATH" >>$GITHUB_ENV
       - name: Install dependencies