ci: nodejs12 is deprecated

move audit-check to the one maintained by `rustsec` to stand away from
nodejs 12.

See actions-rs/audit-check#227

.github/workflows/security-audit.yml

@@ -21,7 +21,7 @@ jobs:
         with:
           path: ~/.cargo/bin
           key: ${{ runner.os }}-cargo-audit-v0.15.2
-      - uses: actions-rs/audit-check@v1
+      - uses: rustsec/audit-check@v1
         with:
           token: ${{ secrets.GITHUB_TOKEN }}