Merge pull request #3255 from stan-dev/dependabot/github_actions/actions/checkout-6

Bump actions/checkout from 5 to 6

Author: WardBrian

.github/workflows/header_checks.yml

@@ -26,7 +26,7 @@ jobs:
     runs-on: windows-latest
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - uses: actions/setup-python@v6
       with:
         python-version: '3.x'
@@ -52,7 +52,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
 
     - name: Run header tests
       run: |
@@ -63,7 +63,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
 
     - name: Run header tests
       run: |

.github/workflows/main.yml

@@ -36,7 +36,7 @@ jobs:
         ]
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - uses: actions/setup-python@v6
       with:
         python-version: '3.x'
@@ -87,7 +87,7 @@ jobs:
         group: [1, 2, 3, 4, 5]
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - uses: actions/setup-python@v6
       with:
         python-version: '3.x'