chore(deps): update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/build.yml

@@ -9,7 +9,7 @@ jobs:
       matrix:
         os: [ubuntu-latest] #, macos-latest, windows-latest]
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Install latest nightly
         uses: actions-rs/toolchain@v1
         with: