Bump actions/checkout from 5 to 6 in the github-actions group

Bumps the github-actions group with 1 update: [actions/checkout](https://github.com/actions/checkout).


Updates `actions/checkout` from 5 to 6
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v5...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: github-actions
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/build_latest.yml

@@ -17,7 +17,7 @@ jobs:
         python-version: ["3.14"]
     steps:
 
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         submodules: true
 

.github/workflows/build_master.yml

@@ -14,7 +14,7 @@ jobs:
         python-version: ["3.14"]
     steps:
 
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         submodules: true
 

.github/workflows/build_old.yml

@@ -17,7 +17,7 @@ jobs:
         python-version: ["3.14"]
     steps:
 
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         submodules: true
 

.github/workflows/cibuildwheel.yml

@@ -18,7 +18,7 @@ jobs:
     name: Build source distribution
     runs-on: ubuntu-22.04
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
 
@@ -63,7 +63,7 @@ jobs:
             arch: x86_64
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         fetch-depth: 0
 
@@ -108,7 +108,7 @@ jobs:
         arch: [AMD64]
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
 

.github/workflows/miniconda.yml

@@ -24,7 +24,7 @@ jobs:
         shell: bash -l {0}
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         submodules: true
 
@@ -60,7 +60,7 @@ jobs:
       run:
         shell: bash -l {0}
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         submodules: true