build(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/backtest.yml

@@ -44,7 +44,7 @@ jobs:
         run: |
           sudo killall firedancer-dev || true
 
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: recursive
 

.github/workflows/benchmark.yml

@@ -32,7 +32,7 @@ jobs:
 
     steps:
     - name: Checkout current commit
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
 
     - uses: ./.github/actions/deps
       with:
@@ -49,7 +49,7 @@ jobs:
     - run: echo OBJDIR=$(make help | grep OBJDIR | awk '{print $4}') >> $GITHUB_ENV
 
     - name: Checkout main for baseline
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         ref: main
         clean: false
@@ -78,7 +78,7 @@ jobs:
         echo DEFAULT_MEM_BASELINE=$DEFAULT_MEM_BASELINE >> $GITHUB_ENV
 
     - name: Checkout new changes
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         clean: false
 

.github/workflows/book.yml

@@ -25,7 +25,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0 # Not needed if lastUpdated is not enabled
       # - uses: pnpm/action-setup@v2 # Uncomment this if you're using pnpm

.github/workflows/builds.yml

@@ -96,7 +96,7 @@ jobs:
       group: fd-public-repo
     if: ${{ inputs.gcc != 'none' }}
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: recursive
 
@@ -151,7 +151,7 @@ jobs:
       group: fd-public-repo
     if: ${{ inputs.clang != 'none' }}
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: recursive
 
@@ -209,7 +209,7 @@ jobs:
       matrix:
         gcc_version: [12]
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: recursive
 

.github/workflows/check_seccomp.yml

@@ -11,7 +11,7 @@ jobs:
 
     steps:
       - name: Checkout current commit
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
 

.github/workflows/clusterfuzz.yml

@@ -13,7 +13,7 @@ jobs:
       COV_OBJ_DIR: build/cov
       EXTRAS: fuzz # asan
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: recursive
 
@@ -88,7 +88,7 @@ jobs:
       MACHINE: ${{ matrix.machine }}
       EXTRAS: fuzz asan ubsan
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: recursive
 

.github/workflows/codeql.yml

@@ -29,7 +29,7 @@ jobs:
       CC: ${{ matrix.compiler }}
       CXX: ${{ matrix.compiler == 'gcc' && 'g++' || 'clang++' }}
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: recursive
       - uses: ./.github/actions/deps

.github/workflows/coverage_report.yml

@@ -17,7 +17,7 @@ jobs:
       name: coverage-report
       url: ${{ vars.COVERAGE_URL }}
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: recursive
 

.github/workflows/coverage_report_clusterfuzz.yml

@@ -15,7 +15,7 @@ jobs:
       MACHINE: linux_clang_haswell
       EXTRAS: llvm-cov
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: recursive
 

.github/workflows/doxygen.yml

@@ -14,7 +14,7 @@ jobs:
       name: doxygen
       url: ${{ vars.DOXYGEN_URL }}
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: 'google-github-actions/setup-gcloud@v3'
 
       - name: Dependencies