Update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/ci.yml

@@ -15,7 +15,7 @@ jobs:
     env:
       RUSTFLAGS: -D warnings
     steps:
-      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
       - uses: dtolnay/rust-toolchain@stable
         with:
           components: rustfmt, clippy
@@ -43,7 +43,7 @@ jobs:
     env:
       RUSTFLAGS: -D warnings
     steps:
-      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
       - uses: dtolnay/rust-toolchain@master
         with:
           toolchain: ${{ matrix.rust-version }}
@@ -66,7 +66,7 @@ jobs:
         rust-version: [nightly]
       fail-fast: false
     steps:
-      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
       - uses: dtolnay/rust-toolchain@master
         with:
           toolchain: ${{ matrix.rust-version }}
@@ -89,7 +89,7 @@ jobs:
         rust-version: [stable]
       fail-fast: false
     steps:
-      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
       - uses: dtolnay/rust-toolchain@master
         with:
           toolchain: ${{ matrix.rust-version }}

.github/workflows/coverage.yml

@@ -17,7 +17,7 @@ jobs:
     env:
       RUSTFLAGS: -D warnings
     steps:
-      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
       - uses: dtolnay/rust-toolchain@nightly  # Use nightly to get access to coverage --doc
         with:
           components: llvm-tools-preview

.github/workflows/docs.yml

@@ -11,7 +11,7 @@ jobs:
     concurrency: ci-${{ github.ref }}
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
       - uses: dtolnay/rust-toolchain@stable
       - uses: Swatinem/rust-cache@a95ba195448af2da9b00fb742d14ffaaf3c21f43 # v2
       - name: Build rustdoc

.github/workflows/release.yml

@@ -15,7 +15,7 @@ jobs:
       id-token: write     # Required for OIDC token exchange
       contents: write     # Required for creating releases
     steps:
-      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
         with:
           persist-credentials: false
       - uses: rust-lang/crates-io-auth-action@v1