ci/gha: bump go 1.16-rc1 -> 1.16.x

As the final go 1.16 is released, rc1 is no longer available.

Signed-off-by: Kir Kolyshkin <[email protected]>

Author: kolyshkin

.github/workflows/test.yml

@@ -19,7 +19,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        go-version: [1.14.x, 1.15.x, 1.16.0-rc1]
+        go-version: [1.14.x, 1.15.x, 1.16.x]
         rootless: ["rootless", ""]
 
     steps: