ci: update golangci-lint to latest version

The latest lint job for main failed with many errors [1] despite the
same tree passing before the PR was merged [2].  The lint job pulls in
the latest stable Go, so it's likely that the failure is due to some
interaction between golangci-lint and the Go 1.23 update.

Update golangci-lint to its latest version to resolve the failure.

[1]: https://github.com/metrumresearchgroup/bbi/actions/runs/10395527571/job/28787806080
[2]: https://github.com/metrumresearchgroup/bbi/actions/runs/10379044354/job/28736486108

.github/workflows/lint.yml

@@ -17,4 +17,4 @@ jobs:
       - name: Run golangci-lint
         uses: golangci/golangci-lint-action@v6
         with:
-          version: v1.59
+          version: v1.60