Update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/format.yml

@@ -9,7 +9,7 @@ jobs:
 
     steps:
       - name: Checkout project
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           ref: ${{ github.head_ref }}
           fetch-depth: 0

.github/workflows/main.yml

@@ -37,7 +37,7 @@ jobs:
           access_token: ${{ github.token }}
 
       - name: Checkout Code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Install Rust
         run: |
@@ -70,7 +70,7 @@ jobs:
 
     steps:
       - name: Checkout Code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Get Current Date
         id: date