chore(deps): update actions/checkout action to v4 (#18)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

.github/workflows/audit.yml

@@ -36,7 +36,7 @@ jobs:
     name: Run cargo-deny
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3
+      - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
 
       - uses: EmbarkStudios/cargo-deny-action@a50c7d5f86370e02fae8472c398f15a36e517bb8 # v1
         with: