Update common Prometheus files (#266)

Signed-off-by: prombot <prometheus-team@googlegroups.com>

Author: prombot

.github/workflows/govulncheck.yml

@@ -22,3 +22,5 @@ jobs:
     steps:
       - id: govulncheck
         uses: golang/govulncheck-action@b625fbe08f3bccbe446d94fbf87fcc875a4f50ee # v1.0.4
+        env:
+          GOOS: ${{ contains(github.repository, 'windows_exporter') && 'windows' || '' }}