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]>

.github/workflows/ci.yml

@@ -34,7 +34,7 @@ jobs:
             python-version: "3.8"
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Base Setup
         uses: jupyterlab/maintainer-tools/.github/actions/base-setup@v1
@@ -70,7 +70,7 @@ jobs:
     needs:
       - build
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: jupyterlab/maintainer-tools/.github/actions/report-coverage@v1
         with:
           fail_under: 80
@@ -79,7 +79,7 @@ jobs:
     name: Test Lint
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: jupyterlab/maintainer-tools/.github/actions/base-setup@v1
       -  name: Run Linters
          run: |
@@ -91,7 +91,7 @@ jobs:
   check_release:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: jupyterlab/maintainer-tools/.github/actions/base-setup@v1
       - uses: jupyter-server/jupyter_releaser/.github/actions/check-release@v2
         with:
@@ -100,7 +100,7 @@ jobs:
   test_docs:
     runs-on: windows-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: jupyterlab/maintainer-tools/.github/actions/base-setup@v1
       - name: Build API docs
         run: |
@@ -122,7 +122,7 @@ jobs:
         python-version: ["3.9"]
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Base Setup
         uses: jupyterlab/maintainer-tools/.github/actions/base-setup@v1
@@ -145,7 +145,7 @@ jobs:
     timeout-minutes: 20
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Base Setup
         uses: jupyterlab/maintainer-tools/.github/actions/base-setup@v1
         with:
@@ -165,7 +165,7 @@ jobs:
     timeout-minutes: 20
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Base Setup
         uses: jupyterlab/maintainer-tools/.github/actions/base-setup@v1
         with:
@@ -179,7 +179,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 20
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: jupyterlab/maintainer-tools/.github/actions/base-setup@v1
       - uses: jupyterlab/maintainer-tools/.github/actions/make-sdist@v1
 
@@ -195,7 +195,7 @@ jobs:
   link_check:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: jupyterlab/maintainer-tools/.github/actions/base-setup@v1
       - uses: jupyterlab/maintainer-tools/.github/actions/check-links@v1
 

.github/workflows/downstream.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Base Setup
         uses: jupyterlab/maintainer-tools/.github/actions/base-setup@v1
@@ -29,7 +29,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Base Setup
         uses: jupyterlab/maintainer-tools/.github/actions/base-setup@v1
@@ -44,7 +44,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Base Setup
         uses: jupyterlab/maintainer-tools/.github/actions/base-setup@v1
@@ -58,7 +58,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Base Setup
         uses: jupyterlab/maintainer-tools/.github/actions/base-setup@v1
@@ -73,7 +73,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Base Setup
         uses: jupyterlab/maintainer-tools/.github/actions/base-setup@v1
@@ -90,7 +90,7 @@ jobs:
     timeout-minutes: 20
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Setup Python
         uses: actions/setup-python@v4
         with:
@@ -122,7 +122,7 @@ jobs:
     timeout-minutes: 20
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Setup Python
         uses: actions/setup-python@v4
         with: