chore(deps): bump actions/checkout from 4 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 4 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v4...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] <support@github.com>

Author: dependabot[bot]

.github/workflows/contract.yaml

@@ -19,7 +19,7 @@ jobs:
     steps:
       - id: checkout
         name: Checkout Repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - id: setup
         name: Setup Toolchain

.github/workflows/coverage.yaml

@@ -19,7 +19,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Install LLVM tools
         run: sudo apt-get update && sudo apt-get install -y llvm

.github/workflows/generate_coverage_pr.yaml

@@ -19,7 +19,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Install LLVM tools
         run: sudo apt-get update && sudo apt-get install -y llvm

.github/workflows/testing.yaml

@@ -15,7 +15,7 @@ jobs:
     steps:
       - id: checkout
         name: Checkout Repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - id: setup
         name: Setup Toolchain
@@ -44,7 +44,7 @@ jobs:
     steps:
       - id: checkout
         name: Checkout Repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - id: setup
         name: Setup Toolchain
@@ -97,7 +97,7 @@ jobs:
     steps:
       - id: checkout
         name: Checkout Repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - id: setup
         name: Setup Toolchain

.github/workflows/upload_coverage_pr.yaml

@@ -96,7 +96,7 @@ jobs:
           echo "override_commit=$(<commit_sha.txt)" >> "$GITHUB_OUTPUT"
 
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           ref: ${{ steps.parse_previous_artifacts.outputs.override_commit || '' }}
           path: repo_root