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] <support@github.com>

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -12,7 +12,7 @@ jobs:
   Rustfmt:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@nightly
         with:
           components: rustfmt
@@ -36,7 +36,7 @@ jobs:
         package: [askama_web, askama_web_derive]
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@nightly
       - uses: Swatinem/rust-cache@v2
       - run: cd ${{ matrix.package }} && cargo doc --all-features --no-deps
@@ -46,15 +46,15 @@ jobs:
   Audit:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: EmbarkStudios/cargo-deny-action@v2
         with:
           manifest-path: ./askama_web/Cargo.toml
 
   Typos:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: crate-ci/typos@master
 
   DevSkim:
@@ -65,7 +65,7 @@ jobs:
       contents: read
       security-events: write
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Run DevSkim scanner
         uses: microsoft/DevSkim-Action@v1
@@ -79,7 +79,7 @@ jobs:
     name: Check order in Cargo.toml
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - run: cargo install --git https://github.com/DevinR528/cargo-sort.git
       - run: |
           set -euo pipefail
@@ -108,7 +108,7 @@ jobs:
         ]
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@stable
         with:
           components: clippy
@@ -123,7 +123,7 @@ jobs:
   MSRV:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@master
         with:
           toolchain: "1.83.0"