chore(deps): bump actions/checkout from 4 to 5

Bumps [actions/checkout](https://github.com/actions/checkout) from 4 to 5.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v4...v5)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -24,7 +24,7 @@ jobs:
     if: github.repository == 'graphql-rust/graphql-client'
     steps:
     - name: Checkout sources
-      uses: actions/checkout@v4
+      uses: actions/checkout@v5
     - name: Install toolchain
       uses: dtolnay/rust-toolchain@master
       with:
@@ -37,7 +37,7 @@ jobs:
     if: github.repository == 'graphql-rust/graphql-client'
     steps:
     - name: Checkout sources
-      uses: actions/checkout@v4
+      uses: actions/checkout@v5
     - name: Install toolchain
       uses: dtolnay/rust-toolchain@stable
       with:
@@ -50,15 +50,15 @@ jobs:
     name: Rustfmt
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
     - uses: dtolnay/rust-toolchain@stable
     - run: cargo fmt --all -- --check
 
   lint:
     name: Clippy
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: dtolnay/rust-toolchain@master
         with:
           toolchain: ${{ env.clippy_rust_version }}