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/docker.yml

@@ -33,7 +33,7 @@ jobs:
           - 5.8.1
           - 5.9
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
       - run: git clone --depth 1 -- https://github.com/z-shell/zi.git zi
@@ -66,7 +66,7 @@ jobs:
   build-latest:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
       - run: git clone --depth 1 -- https://github.com/z-shell/zi.git zi

.github/workflows/rebase.yml

@@ -16,7 +16,7 @@ jobs:
       )
     steps:
       - name: Checkout the latest code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
           fetch-depth: 0 # otherwise, you will fail to push refs to dest repo

.github/workflows/zsh-n.yml

@@ -17,7 +17,7 @@ jobs:
       matrix: ${{ steps.set-matrix.outputs.matrix }}
     steps:
       - name: ⤵️ Check out code from GitHub
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           submodules: recursive
       - name: "✨ Set matrix output"
@@ -35,7 +35,7 @@ jobs:
       matrix: ${{ fromJSON(needs.zsh-matrix.outputs.matrix) }}
     steps:
       - name: ⤵️ Check out code from GitHub
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           submodules: recursive
       - name: "⚡ Install dependencies"

.github/workflows/zunit.yml

@@ -18,7 +18,7 @@ jobs:
     outputs:
       matrix: ${{ steps.set-matrix.outputs.matrix }}
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: "Set matrix output"
         id: set-matrix
         run: |
@@ -39,7 +39,7 @@ jobs:
           registry: ghcr.io
           username: ${{ github.repository_owner }}
           password: ${{ secrets.GITHUB_TOKEN }}
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - run: command git clone --branch ${{ env.zi_branch }} --depth 1 -- https://github.com/z-shell/zi.git zi
       - name: "⚡ Install dependencies"
         run: |