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

Author: renovate[bot]

.github/workflows/flagd-ofrep-check.yml

@@ -17,7 +17,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: recursive
 

.github/workflows/release-please.yml

@@ -42,7 +42,7 @@ jobs:
         path: ${{ fromJSON(needs.release-please.outputs.paths_released || '[]') }}
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: recursive
 

.github/workflows/rust.yml

@@ -20,7 +20,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         submodules: recursive
 
@@ -42,7 +42,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Check formats
         run: cargo fmt --check