chore(deps): update actions/checkout action to v6 (#235)

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
@@ -53,7 +53,7 @@ jobs:
 
         steps:
             - name: Checkout
-              uses: actions/checkout@v5
+              uses: actions/checkout@v6
 
             # TODO: Investigate why tests fail on stable toolchain.
             - name: Set up Rust toolchain

.github/workflows/release.yml

@@ -29,7 +29,7 @@ jobs:
                   private_key: ${{ secrets.APP_PRIVATE_KEY }}
 
             - 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/upstream.yml

@@ -16,7 +16,7 @@ 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

@@ -18,7 +18,7 @@ jobs:
         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
@@ -41,7 +41,7 @@ jobs:
         runs-on: ubuntu-latest
 
         steps:
-            - uses: actions/checkout@v5
+            - uses: actions/checkout@v6
               with:
                   fetch-depth: 0
 
@@ -87,7 +87,7 @@ jobs:
             id-token: write
 
         steps:
-            - uses: actions/checkout@v5
+            - uses: actions/checkout@v6
               with:
                   fetch-depth: 0