chore(ci): bump GitHub Actions to latest versions

Update GitHub Actions across all workflows:
- actions/checkout: 5.0.0 -> 6.0.1
- actions/setup-node: 5.0.0 -> 6.1.0

All SHAs verified against GitHub releases.

Author: jdalton

.github/workflows/generate.yml

@@ -38,7 +38,7 @@ jobs:
           echo "Sleeping for $delay seconds..."
           sleep $delay
 
-      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
         with:
           autocrlf: false
           persist-credentials: false
@@ -140,7 +140,7 @@ jobs:
     outputs:
       has_changes: ${{ steps.check.outputs.has_changes }}
     steps:
-      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
         with:
           autocrlf: false
           persist-credentials: false