Bump actions/checkout from 3 to 4

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] <[email protected]>

Author: dependabot[bot]

.github/workflows/docs.yml

@@ -10,7 +10,7 @@ jobs:
   check-links:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
       with:
         submodules: 'recursive'
 
@@ -58,7 +58,7 @@ jobs:
   check-warnings:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
       with:
         submodules: 'recursive'
 

.github/workflows/python-package.yml

@@ -42,7 +42,7 @@ jobs:
       OTIO_CONSUMER_TEST_BUILD_DIR: ${{ github.workspace }}/consumertest
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
       with:
         submodules: 'recursive'
     - name: Install coverage dependency
@@ -109,7 +109,7 @@ jobs:
       OTIO_CXX_BUILD_TMP_DIR: ${{ github.workspace }}/build
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
       with:
         submodules: 'recursive'
     - name: Set up MSYS2
@@ -166,7 +166,7 @@ jobs:
         os: [ubuntu-22.04, windows-2022, macos-12]
         python-build: ['cp37*', 'cp38*', 'cp39*', 'cp310*', 'cp311*', 'cp312*']
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: Build wheels (Python 3)
         uses: pypa/[email protected]
@@ -187,7 +187,7 @@ jobs:
     needs: py_build_test
     runs-on: ubuntu-22.04
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
       with:
         submodules: 'recursive'