build(deps): 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] <support@github.com>

Author: dependabot[bot]

.github/workflows/autopush.yml

@@ -10,7 +10,7 @@ jobs:
         if: startsWith(github.repository, 'inducer/')
         runs-on: ubuntu-latest
         steps:
-        -   uses: actions/checkout@v5
+        -   uses: actions/checkout@v6
         -   run: |
                 curl -L -O https://tiker.net/ci-support-v0
                 . ./ci-support-v0

.github/workflows/ci.yml

@@ -18,7 +18,7 @@ jobs:
         name: Ruff
         runs-on: ubuntu-latest
         steps:
-        -   uses: actions/checkout@v5
+        -   uses: actions/checkout@v6
         -   uses: actions/setup-python@v6
         -   name: "Main Script"
             run: |
@@ -29,14 +29,14 @@ jobs:
         name: Typos
         runs-on: ubuntu-latest
         steps:
-        -   uses: actions/checkout@v5
+        -   uses: actions/checkout@v6
         -   uses: crate-ci/typos@master
 
     validate_cff:
         name: Validate CITATION.cff
         runs-on: ubuntu-latest
         steps:
-        -   uses: actions/checkout@v5
+        -   uses: actions/checkout@v6
         -   uses: actions/setup-python@v6
             with:
                 python-version: '3.x'
@@ -48,7 +48,7 @@ jobs:
         name: Pylint
         runs-on: ubuntu-latest
         steps:
-        -   uses: actions/checkout@v5
+        -   uses: actions/checkout@v6
         -
             uses: actions/setup-python@v6
             with:
@@ -62,7 +62,7 @@ jobs:
     basedpyright:
         runs-on: ubuntu-latest
         steps:
-        -   uses: actions/checkout@v5
+        -   uses: actions/checkout@v6
         -   uses: actions/setup-python@v6
             with:
                 python-version: '3.x'
@@ -87,7 +87,7 @@ jobs:
                 python-version: ["3.10", "3.12", "3.x", "pypy3.10"]
                 os: [ubuntu-latest, macos-latest]
         steps:
-        -   uses: actions/checkout@v5
+        -   uses: actions/checkout@v6
         -
             uses: actions/setup-python@v6
             with:
@@ -110,7 +110,7 @@ jobs:
         name: Pytest without Numpy
         runs-on: ubuntu-latest
         steps:
-        -   uses: actions/checkout@v5
+        -   uses: actions/checkout@v6
         -
             uses: actions/setup-python@v6
             with:
@@ -125,7 +125,7 @@ jobs:
     #    name: Examples Py3
     #    runs-on: ubuntu-latest
     #    steps:
-    #    -   uses: actions/checkout@v5
+    #    -   uses: actions/checkout@v6
     #    -
     #        uses: actions/setup-python@v6
     #        with:
@@ -145,7 +145,7 @@ jobs:
         name: Tests for downstream project ${{ matrix.downstream_project }}
         runs-on: ubuntu-latest
         steps:
-        -   uses: actions/checkout@v5
+        -   uses: actions/checkout@v6
         -   name: "Main Script"
             env:
                 DOWNSTREAM_PROJECT: ${{ matrix.downstream_project }}
@@ -158,7 +158,7 @@ jobs:
         name: Documentation
         runs-on: ubuntu-latest
         steps:
-        -   uses: actions/checkout@v5
+        -   uses: actions/checkout@v6
         -
             uses: actions/setup-python@v6
             with:

.github/workflows/release.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         persist-credentials: false
     - name: Set up Python