Bump actions/checkout from 3 to 4 (#122)

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v3...v4)

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

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/build_wheels.yml

@@ -41,7 +41,7 @@ jobs:
 
     steps:
       - name: Checkout scikit-tree
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - uses: actions/setup-python@v4.6.1
         with:
@@ -94,7 +94,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Set up Python
         uses: actions/setup-python@v4.6.1
@@ -126,7 +126,7 @@ jobs:
 
     steps:
       - name: Checkout scikit-tree
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Setup Python
         uses: actions/setup-python@v4

.github/workflows/main.yml

@@ -42,7 +42,7 @@ jobs:
       FORCE_SUBMODULE: True
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Setup Python ${{ matrix.python-version }}
         uses: actions/setup-python@v4.6.1
@@ -150,7 +150,7 @@ jobs:
     if: startsWith(github.ref, 'refs/tags/')
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Setup Python ${{ matrix.python-version }}
         uses: actions/setup-python@v4.6.1
         with:
@@ -193,7 +193,7 @@ jobs:
     #   runs-on: windows-2019
     #   steps:
     #     - name: Checkout
-    #       uses: actions/checkout@v3
+    #       uses: actions/checkout@v4
     #       with:
     #         submodules: recursive
 

.github/workflows/pr_checks.yml

@@ -22,7 +22,7 @@ jobs:
         run: |
           echo "PR_NUMBER=${{ github.event.pull_request.number }}" >> $GITHUB_ENV
           echo "TAGGED_MILESTONE=${{ github.event.pull_request.milestone.title }}" >> $GITHUB_ENV
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           fetch-depth: "0"
       - name: Check that CHANGELOG has been updated

.github/workflows/style.yml

@@ -31,7 +31,7 @@ jobs:
         poetry-version: [1.3.0]
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Setup Python 3.10
         uses: actions/setup-python@v4.6.1
         with: