chore(deps): bump actions/checkout from 5 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 5 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v5...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/bench.yml

@@ -17,7 +17,7 @@ jobs:
     permissions:
       contents: read
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: true
       - name: Checkout submodules
@@ -47,7 +47,7 @@ jobs:
       BASELINE: base
       IAI_CALLGRIND_RUNNER: iai-callgrind-runner
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: true
       - name: Checkout submodules
@@ -58,7 +58,7 @@ jobs:
       - name: Install cargo-binstall
         uses: taiki-e/install-action@cargo-binstall
       - name: Checkout base
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           ref: ${{ github.base_ref || 'main' }}
           fetch-depth: 2
@@ -73,7 +73,7 @@ jobs:
       - name: Save baseline
         run: cargo bench -p solar-bench --bench iai --features ci -- --save-baseline=$BASELINE
       - name: Checkout PR
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           clean: false
       - name: Install iai-callgrind-runner

.github/workflows/ci.yml

@@ -28,7 +28,7 @@ jobs:
           - os: "ubuntu-latest"
             rust: "nightly"
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: true
       - name: Checkout submodules
@@ -57,7 +57,7 @@ jobs:
     permissions:
       contents: read
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@nightly
       - uses: taiki-e/install-action@cargo-hack
       - uses: Swatinem/rust-cache@v2
@@ -72,7 +72,7 @@ jobs:
     permissions:
       contents: read
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: crate-ci/typos@v1
 
   clippy:
@@ -81,7 +81,7 @@ jobs:
     permissions:
       contents: read
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@clippy
       - uses: Swatinem/rust-cache@v2
         with:
@@ -96,7 +96,7 @@ jobs:
     permissions:
       contents: read
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@nightly
       - uses: Swatinem/rust-cache@v2
         with:
@@ -112,7 +112,7 @@ jobs:
     permissions:
       contents: read
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@nightly
         with:
           components: rustfmt
@@ -133,7 +133,7 @@ jobs:
             build-mode: none
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           persist-credentials: false
       - name: Initialize CodeQL