use latest go 1.x available (#4794)

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

.github/workflows/go.tidy.yml

@@ -8,6 +8,12 @@ jobs:
   fix:
     runs-on: ubuntu-latest
     steps:
+      -
+        name: Install Go
+          uses: actions/setup-go@v2
+          with:
+            go-version: '^1.16'
+          id: go
       -
         name: Checkout
         uses: actions/checkout@v2