Bump actions/checkout from 2 to 4

Bumps [actions/checkout](https://github.com/actions/checkout) from 2 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v2...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/tests.yml

@@ -20,7 +20,7 @@ jobs:
     # Run npm build and check that the dist/ folder is up to date.
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: Build
         run: |
           npm install
@@ -39,7 +39,7 @@ jobs:
           - { os: windows-latest, shell: powershell, variant: ccache, xfail: true }
     runs-on: ${{ matrix.os }}
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: Run ccache-action
         id: ccache
         uses: ./
@@ -96,7 +96,7 @@ jobs:
           - { os: windows-latest, shell: powershell, variant: ccache }
     runs-on: ${{ matrix.os }}
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: Run ccache action
         uses: ./
         id: output
@@ -121,7 +121,7 @@ jobs:
           - { os: windows-latest, shell: powershell, variant: ccache }
     runs-on: ${{ matrix.os }}
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - run: |
           echo "RAND=$RANDOM" >> $GITHUB_ENV
       - name: Run ccache action
@@ -148,7 +148,7 @@ jobs:
           - { os: windows-latest, shell: powershell, variant: ccache }
     runs-on: ${{ matrix.os }}
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - run: |
           echo "RAND=$RANDOM" >> $GITHUB_ENV
       - name: Run ccache action
@@ -168,7 +168,7 @@ jobs:
     runs-on: ubuntu-latest
     container: ubuntu:latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - run: apt update
         shell: bash
       - name: Run ccache-action
@@ -179,7 +179,7 @@ jobs:
     runs-on: ubuntu-latest
     container: alpine:latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - run: apk update
         shell: sh
       - name: Run ccache-action
@@ -192,7 +192,7 @@ jobs:
       matrix:
         save: [true, false]
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: Run ccache-action
         uses: ./
         with:
@@ -205,7 +205,7 @@ jobs:
       matrix:
         append-timestamp: [true, false]
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: Run ccache-action
         uses: ./
         with:
@@ -218,7 +218,7 @@ jobs:
       matrix:
         create-symlink: [true, false]
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: Run ccache-action
         uses: ./
         with: