CI: (deps): Bump actions/checkout from 5 to 6 in /.github/workflows

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/backport-prs.yml

@@ -39,7 +39,7 @@ jobs:
           git config --global user.email '${{ steps.get-user-id.outputs.user-id }}+${{ steps.app-token.outputs.app-slug }}[bot]@users.noreply.github.com'
 
       - name: Checkout PR HEAD
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           ref: ${{ github.event.pull_request.head.sha }}
           fetch-depth: 100

.github/workflows/benchmark-pr.yml

@@ -25,7 +25,7 @@ jobs:
             with:
               python-version: "3.12"
           - name: Checkout repo
-            uses: actions/checkout@v5  #checks out repository
+            uses: actions/checkout@v6  #checks out repository
             with:
               fetch-depth: 0  # Fetch full history
           - run: python -m pip install numpy pandas xarray metpy netcdf4

.github/workflows/cffcheck.yml

@@ -17,7 +17,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out a copy of the repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           persist-credentials: false
 

.github/workflows/code-analysis.yml

@@ -28,7 +28,7 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         persist-credentials: false
 

.github/workflows/docs-conda.yml

@@ -33,7 +33,7 @@ jobs:
 
     steps:
     - name: Checkout source
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         fetch-depth: 150
         fetch-tags: true

.github/workflows/docs.yml

@@ -34,7 +34,7 @@ jobs:
 
     steps:
     - name: Checkout source
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         fetch-depth: 150
         persist-credentials: false
@@ -107,7 +107,7 @@ jobs:
 
     steps:
     - name: Checkout docs
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         ref: "gh-pages"
 

.github/workflows/linting.yml

@@ -14,7 +14,7 @@ jobs:
     name: Run Lint Tools
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           persist-credentials: false
 

.github/workflows/release.yml

@@ -10,7 +10,7 @@ jobs:
     name: Build Release Packages
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         persist-credentials: false
 

.github/workflows/tests-conda.yml

@@ -38,7 +38,7 @@ jobs:
 
     steps:
     - name: Checkout source
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         fetch-depth: 150
         fetch-tags: true
@@ -66,7 +66,7 @@ jobs:
     timeout-minutes: 2
     steps:
       - name: Checkout source
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           persist-credentials: false
 

.github/workflows/tests-pypi.yml

@@ -40,7 +40,7 @@ jobs:
 
     steps:
     - name: Checkout source
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         fetch-depth: 150
         fetch-tags: true
@@ -92,7 +92,7 @@ jobs:
     timeout-minutes: 2
     steps:
       - name: Checkout source
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           persist-credentials: false