Update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/build_on_push.yml

@@ -14,7 +14,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
       - name: Install rust toolchain
         uses: actions-rs/toolchain@v1
         with:
@@ -37,7 +37,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
       - name: Ensure that clippy is installed
         uses: actions-rs/toolchain@v1
         with:

.github/workflows/release.yml

@@ -13,7 +13,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
       - name: Log in
         run: cargo login --verbose ${{ secrets.CRATES_TOKEN }}
       - name: Publish Release