chore(deps): bump SocketDev/socket-basics to v3.1.0 (#2)

Bumps the pinned digest from 6b71cdf (v3.0.0) to 5b615c8 (v3.1.0).

v3.1.0 is a minor, backwards-compatible release. Notable fixes relevant
to how this workflow invokes the action:

- changed_files resolved to zero files inside the Docker container action
  because of a git dubious-ownership error (SocketDev/socket-basics#105)
- changed_files was not honored from every config source, and failed
  silently when it was not (SocketDev/socket-basics#98)

Both bugs could cause the scan to silently cover no files, so this is a
correctness fix for PR-scoped scanning, not just a version refresh.

Digest verified against the v3.1.0 tag via the GitHub API.

Author: william-u10d

.github/workflows/security.yaml

@@ -38,7 +38,7 @@ jobs:
         # App instead (server-side auth, no key in the Actions context). This
         # keeps the API key on trusted, same-repo events only.
         if: github.event.pull_request.head.repo.full_name == github.repository
-        uses: SocketDev/socket-basics@6b71cdf3f792e1ba15b0c42133d8a6f29fb1fc4f # v3.0.0
+        uses: SocketDev/socket-basics@5b615c89d17764ab46de2f2de63122ca2ef6a4be # v3.1.0
         continue-on-error: true
         env:
           GITHUB_PR_NUMBER: ${{ github.event.pull_request.number || github.event.issue.number }}