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

Author: renovate[bot]

.github/workflows/build.yml

@@ -14,7 +14,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: Swatinem/rust-cache@v2
       - uses: rui314/setup-mold@v1
       - name: Set up NASM

.github/workflows/reviewdog.yml

@@ -4,7 +4,7 @@ jobs:
   clippy:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Install clippy
         uses: dtolnay/rust-toolchain@stable
         with: