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] <[email protected]>

Author: dependabot[bot]

.github/workflows/audit.yml

@@ -23,7 +23,7 @@ jobs:
       contents: read
       issues: write
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           persist-credentials: false
       - uses: actions-rust-lang/audit@v1

.github/workflows/code_coverage.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           persist-credentials: false
       - name: Install lcov tools

.github/workflows/cont_integration.yml

@@ -12,7 +12,7 @@ jobs:
       rust_version: ${{ steps.read_toolchain.outputs.rust_version }}
     steps:
       - name: "Checkout repo"
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           persist-credentials: false
       - name: "Read rust version"
@@ -33,7 +33,7 @@ jobs:
           - --all-features
     steps:
       - name: checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           persist-credentials: false
       - name: Install Rust toolchain
@@ -58,7 +58,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           persist-credentials: false
       - name: Install Rust toolchain
@@ -86,7 +86,7 @@ jobs:
       CFLAGS: -I/usr/include
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           persist-credentials: false
         # Install a recent version of clang that supports wasm32
@@ -109,7 +109,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           persist-credentials: false
       - name: Install Rust toolchain
@@ -129,7 +129,7 @@ jobs:
     permissions:
       checks: write
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           persist-credentials: false
       - uses: actions-rust-lang/setup-rust-toolchain@v1
@@ -154,7 +154,7 @@ jobs:
           - example_esplora
     steps:
       - name: checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           persist-credentials: false
       - name: Install Rust toolchain

.github/workflows/cron-update-rust.yml

@@ -11,7 +11,7 @@ jobs:
     name: Update rustc
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           persist-credentials: false
       - uses: dtolnay/rust-toolchain@stable

.github/workflows/zizmor.yml

@@ -13,7 +13,7 @@ jobs:
       security-events: write
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           persist-credentials: false