Update go version for github action to 1.16

Author: mstemm

.github/workflows/krew-plugin-release.yml

@@ -12,7 +12,7 @@ jobs:
     - name: Setup Go
       uses: actions/setup-go@v1
       with:
-        go-version: 1.14
+        go-version: 1.16
     - name: GoReleaser
       uses: goreleaser/goreleaser-action@v1
       with: