chore(deps): update actions/checkout action to v6 (#65)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/ci.yml

@@ -19,7 +19,7 @@ jobs:
 
         steps:
             - name: Checkout
-              uses: actions/checkout@v5
+              uses: actions/checkout@v6
 
             - name: Set up Rust toolchain
               uses: actions-rust-lang/setup-rust-toolchain@v1
@@ -54,7 +54,7 @@ jobs:
 
         steps:
             - name: Checkout
-              uses: actions/checkout@v5
+              uses: actions/checkout@v6
 
             - name: Set up Rust toolchain
               uses: actions-rust-lang/setup-rust-toolchain@v1

.github/workflows/website.yml

@@ -14,7 +14,7 @@ jobs:
         name: Test Book
         runs-on: ubuntu-latest
         steps:
-            - uses: actions/checkout@v5
+            - uses: actions/checkout@v6
 
             - name: Set up Rust toolchain
               uses: actions-rust-lang/setup-rust-toolchain@v1
@@ -36,7 +36,7 @@ jobs:
         needs: book-test
         runs-on: ubuntu-latest
         steps:
-            - uses: actions/checkout@v5
+            - uses: actions/checkout@v6
               with:
                   fetch-depth: 0
 
@@ -80,7 +80,7 @@ jobs:
             pages: write
             id-token: write
         steps:
-            - uses: actions/checkout@v5
+            - uses: actions/checkout@v6
               with:
                   fetch-depth: 0