Update actions/checkout action to v6 (#526)

Author: renovate[bot]

.github/workflows/build.yaml

@@ -24,7 +24,7 @@ jobs:
   integration:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           lfs: true
 

.github/workflows/docker.yaml

@@ -26,7 +26,7 @@ jobs:
   docker:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - uses: actions/cache@v4
         with:

.github/workflows/test.yaml

@@ -27,7 +27,7 @@ jobs:
     runs-on: namespace-profile-8vcpu-cache
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Install Opus dependencies
         run: sudo apt-get update && sudo apt-get install -y libopus-dev libopusfile-dev libsoxr-dev