Bump actions/checkout from 3 to 4 (#5969)

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/cleanup-docs.yml

@@ -15,7 +15,7 @@ jobs:
           echo "DOCS_OUTPUT_DIR=${GITHUB_WORKSPACE}/skript-docs/docs/nightly/${BRANCH_NAME}" >> $GITHUB_OUTPUT
           echo "DOCS_REPO_DIR=${GITHUB_WORKSPACE}/skript-docs" >> $GITHUB_OUTPUT
       - name: Checkout Skript
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
             ref: ${{ github.event.repository.default_branch }}
             submodules: recursive

.github/workflows/java-17-builds.yml

@@ -12,7 +12,7 @@ jobs:
         if: "! contains(toJSON(github.event.commits.*.message), '[ci skip]')"
         runs-on: ubuntu-latest
         steps:
-            - uses: actions/checkout@v3
+            - uses: actions/checkout@v4
               with:
                   submodules: recursive
             - name: Set up JDK 17

.github/workflows/java-8-builds.yml

@@ -12,7 +12,7 @@ jobs:
         if: "! contains(toJSON(github.event.commits.*.message), '[ci skip]')"
         runs-on: ubuntu-latest
         steps:
-            - uses: actions/checkout@v3
+            - uses: actions/checkout@v4
               with:
                   submodules: recursive
             - name: Set up JDK 17

.github/workflows/junit-17-builds.yml

@@ -12,7 +12,7 @@ jobs:
         if: "! contains(toJSON(github.event.commits.*.message), '[ci skip]')"
         runs-on: ubuntu-latest
         steps:
-            - uses: actions/checkout@v3
+            - uses: actions/checkout@v4
               with:
                   submodules: recursive
             - name: Set up JDK 17

.github/workflows/junit-8-builds.yml

@@ -12,7 +12,7 @@ jobs:
         if: "! contains(toJSON(github.event.commits.*.message), '[ci skip]')"
         runs-on: ubuntu-latest
         steps:
-            - uses: actions/checkout@v3
+            - uses: actions/checkout@v4
               with:
                   submodules: recursive
             - name: Set up JDK 17

.github/workflows/nightly-docs.yml

@@ -29,7 +29,7 @@ jobs:
                 echo "DOCS_REPO_DIR=${GITHUB_WORKSPACE}/skript-docs" >> $GITHUB_OUTPUT
                 echo "SKRIPT_REPO_DIR=${GITHUB_WORKSPACE}/skript" >> $GITHUB_OUTPUT
             - name: Checkout Skript
-              uses: actions/checkout@v3
+              uses: actions/checkout@v4
               with:
                   submodules: recursive
                   path: skript

.github/workflows/release-docs.yml

@@ -17,7 +17,7 @@ jobs:
             echo "DOCS_REPO_DIR=${GITHUB_WORKSPACE}/skript-docs" >> $GITHUB_OUTPUT
             echo "SKRIPT_REPO_DIR=${GITHUB_WORKSPACE}/skript" >> $GITHUB_OUTPUT
         - name: Checkout Skript
-          uses: actions/checkout@v3
+          uses: actions/checkout@v4
           with:
               submodules: recursive
               path: skript
@@ -56,7 +56,7 @@ jobs:
               echo "DOCS_REPO_DIR=${GITHUB_WORKSPACE}/skript-docs" >> $GITHUB_OUTPUT
               echo "SKRIPT_REPO_DIR=${GITHUB_WORKSPACE}/skript" >> $GITHUB_OUTPUT
           - name: Checkout Skript
-            uses: actions/checkout@v3
+            uses: actions/checkout@v4
             with:
                 submodules: recursive
                 path: skript

.github/workflows/repo.yml

@@ -8,7 +8,7 @@ jobs:
     publish:
         runs-on: ubuntu-latest
         steps:
-            - uses: actions/checkout@v3
+            - uses: actions/checkout@v4
               with:
                   submodules: recursive
             - name: Set up JDK 17