build(deps): 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] <support@github.com>

.github/workflows/default-bare.yml

@@ -30,7 +30,7 @@ jobs:
       ANSIBLE_EXTRA_VARS: ""
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           path: juju4.lxd
       - name: Set up Python

.github/workflows/galaxy.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           path: juju4.lxd
       - name: galaxy

.github/workflows/lint.yml

@@ -21,7 +21,7 @@ jobs:
       ANSIBLE_ROLE: juju4.lxd
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           path: ${{ env.ANSIBLE_ROLE }}
       - name: Set up Python