chore: bump golangci-lint timeout (#280)

We've been seeing test failures: https://github.com/theupdateframework/go-tuf/runs/6215906951?check_suite_focus=true

See: golangci/golangci-lint-action#297

Author: znewman01

.github/workflows/tests.yml

@@ -66,3 +66,4 @@ jobs:
         uses: golangci/golangci-lint-action@5c56cd6c9dc07901af25baab6f2b0d9f3b7c3018
         with:
           version: v1.45.2
+          args: --timeout 3m