Bump actions/checkout from 5.0.0 to 6.0.0

.github/workflows/ci-pr.yml

@@ -40,7 +40,7 @@ jobs:
 
     steps:
       - name: Checkout PR branch into cwd
-        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8
         with:
           # Checkout the fork/head-repository to push changes to the fork.
           # Without this the base repository will be checked out and committed to.
@@ -51,7 +51,7 @@ jobs:
           persist-credentials: true
 
       - name: Checkout main branch into directory _main_branch/
-        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8
         with:
           ref: main
           path: _main_branch

.github/workflows/merge.yml

@@ -39,15 +39,15 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
-      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8
         with:
           # Using fetch-depth 0 is the only way to get all tags which are needed for building docs.
           fetch-depth: 0
           # Be specific about keeping credentials (it is the default)
           persist-credentials: true
 
       - name: Checkout gh-pages branch to dir publish/
-        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8
         with:
           ref: gh-pages
           path: publish

.github/workflows/publish.yml

@@ -35,15 +35,15 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
-      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8
         with:
           # Using fetch-depth 0 is the only way to get all tags which are needed for building docs.
           fetch-depth: 0
           # Be specific about keeping credentials (it is the default)
           persist-credentials: true
 
       - name: Checkout gh-pages branch to dir publish/
-        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8
         with:
           ref: gh-pages
           path: publish