Bump actions/checkout from 5 to 6

Bumps [actions/checkout](https://github.com/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
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/CI_PublishTestPyPI.yml

@@ -30,7 +30,7 @@ jobs:
             openblas_path: "/opt/homebrew/opt/openblas"
             py_tag: "cp310"
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: remove python/.gitignore
         shell: bash
         run: |

.github/workflows/PublishPyPI.yml

@@ -75,7 +75,7 @@ jobs:
             openblas_path: "/opt/homebrew/opt/openblas"
             py_tag: "cp313"
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: remove python/.gitignore
         shell: bash
         run: |

.github/workflows/VersionConsistencyCheck.yml

@@ -21,7 +21,7 @@ jobs:
 
     steps:
     - name: Checkout code
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
 
     - name: Set up Python
       uses: actions/setup-python@v6

.github/workflows/conda.yml

@@ -19,7 +19,7 @@ jobs:
             runner_label: macos-latest
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - uses: conda-incubator/setup-miniconda@v3
       with:
         auto-update-conda: true

.github/workflows/test_cxx_backend.yml

@@ -15,7 +15,7 @@ jobs:
         os: [ubuntu-latest, macos-latest]
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Install dependencies (Ubuntu)
         if: runner.os == 'Linux'
@@ -46,7 +46,7 @@ jobs:
     timeout-minutes: 60  # Allow up to 60 minutes for ILP64 tests
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Install dependencies with ILP64 BLAS
         run: |

.github/workflows/test_fortran.yml

@@ -13,7 +13,7 @@ jobs:
     name: Fortran with GCC/gfortran
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Install dependencies
         run: |
@@ -29,7 +29,7 @@ jobs:
     name: Fortran with Intel compilers
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Install Intel oneAPI
         run: |

.github/workflows/test_python.yml

@@ -23,7 +23,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Install system dependencies (Ubuntu)
         if: runner.os == 'Linux'