Update actions/checkout@v5 -> v6

Author: dtolnay

.github/workflows/ci.yml

@@ -27,7 +27,7 @@ jobs:
         rust: [nightly, beta, stable, 1.76.0]
     timeout-minutes: 45
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@master
         with:
           toolchain: ${{matrix.rust}}
@@ -57,7 +57,7 @@ jobs:
             os: windows
     timeout-minutes: 45
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@nightly
       - name: Enable type layout randomization
         run: echo RUSTFLAGS=${RUSTFLAGS}\ -Zrandomize-layout >> $GITHUB_ENV
@@ -71,7 +71,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 45
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@nightly
       - run: cargo generate-lockfile -Z minimal-versions
       - run: cargo check --locked
@@ -85,7 +85,7 @@ jobs:
     env:
       RUSTDOCFLAGS: -Dwarnings
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@nightly
       - uses: dtolnay/install@cargo-docs-rs
       - run: cargo docs-rs
@@ -96,7 +96,7 @@ jobs:
     if: github.event_name != 'pull_request'
     timeout-minutes: 45
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@clippy
       - run: cargo clippy --tests -- -Dclippy::all -Dclippy::pedantic
 
@@ -106,7 +106,7 @@ jobs:
     if: github.event_name != 'pull_request'
     timeout-minutes: 45
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@stable
       - uses: dtolnay/install@cargo-outdated
       - run: cargo outdated --workspace --exit-code 1
@@ -119,7 +119,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 45
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@nightly
       - uses: dtolnay/install@cargo-fuzz
       - run: cargo fuzz check