Bump actions/checkout from 4 to 6

Author: stlankes

.github/workflows/clippy.yml

@@ -18,7 +18,7 @@ jobs:
         os: [ubuntu-latest]
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
       with:
          submodules: true
     - name: Check Cargo availability

.github/workflows/format.yml

@@ -18,7 +18,7 @@ jobs:
         os: [ubuntu-latest]
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
       with:
          submodules: true
     - name: Check Cargo availability

.github/workflows/run.yml

@@ -36,7 +36,7 @@ jobs:
         choco install qemu
         echo "$Env:Programfiles\qemu" | Out-File -FilePath $env:GITHUB_PATH -Encoding utf8 -Append
       shell: pwsh
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
       with:
          submodules: true
          lfs: true