Bump actions/checkout from 5 to 6

.github/workflows/build.yaml

@@ -16,7 +16,7 @@ jobs:
         python-version: ["3.11", "3.12", "3.13", "3.14"]
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           # Need to clone everything for the git tags.
           fetch-depth: 0
@@ -78,7 +78,7 @@ jobs:
     if: startsWith(github.ref, 'refs/tags/')
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           # Need to clone everything to embed the version.
           fetch-depth: 0

.github/workflows/build_docs.yaml

@@ -10,7 +10,7 @@ jobs:
   build_sphinx_docs:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           # Need to clone everything for the git tags.
           fetch-depth: 0

.github/workflows/codeql-analysis.yml

@@ -42,7 +42,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       # Initializes the CodeQL tools for scanning.
       - name: Initialize CodeQL

.github/workflows/do_not_merge.yaml

@@ -26,7 +26,7 @@ jobs:
             'DO NOT MERGE'. Remove this commit from the branch before merging
             or change the commit summary."
 
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Check requirements.txt for branches
         shell: bash

.github/workflows/docstyle.yaml

@@ -14,7 +14,7 @@ jobs:
   numpydoc:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Set up Python
         uses: actions/setup-python@v6