build(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)
- [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] <[email protected]>

Author: dependabot[bot]

.github/workflows/audit.yml

@@ -30,7 +30,7 @@ jobs:
     timeout-minutes: 15
     steps:
       - name: Checkout code
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
+        uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3
 
       - name: Install Rust toolchain
         uses: dtolnay/rust-toolchain@stable

.github/workflows/cont_integration.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Install Rust toolchain
         uses: actions-rust-lang/setup-rust-toolchain@v1
@@ -34,7 +34,7 @@ jobs:
           - --no-default-features
           - --all-features
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Install Rust toolchain
         uses: actions-rust-lang/setup-rust-toolchain@v1
@@ -57,7 +57,7 @@ jobs:
           - --no-default-features
           - --all-features
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Install Rust toolchain
         uses: actions-rust-lang/setup-rust-toolchain@v1
@@ -79,7 +79,7 @@ jobs:
     name: MSRV
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Install Rust toolchain
         uses: actions-rust-lang/setup-rust-toolchain@v1

.github/workflows/zizmor.yml

@@ -20,7 +20,7 @@ jobs:
     timeout-minutes: 10
     steps:
       - name: Checkout repository
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 
+        uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 
 
       - name: Run zizmor 
         uses: zizmorcore/zizmor-action@e639db99335bc9038abc0e066dfcd72e23d26fb4