.github/workflows: change action version

Change-Id: Ic664c074b5291748ed4ef2b10ccc74fa698499da
Reviewed-on: https://go-review.googlesource.com/c/vulndb/+/499462
Reviewed-by: Tatiana Bradley <tatianabradley@google.com>
Reviewed-by: Julie Qiu <julieqiu@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Julie Qiu <julieqiu@google.com>
Auto-Submit: Julie Qiu <julieqiu@google.com>

.github/workflows/govulncheck.yml

@@ -5,4 +5,4 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - id: govulncheck
-        uses: golang/govulncheck-action@v0.1.0-pre.1
+        uses: golang/govulncheck-action@v0.1.0