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/addoncheck-matrix.yml

@@ -8,7 +8,7 @@ jobs:
  runs-on: ubuntu-latest
 
  steps:
- - uses: actions/checkout@v3
+ - uses: actions/checkout@v4
  - name: Set up Python
  uses: actions/setup-python@v4
  with:

.github/workflows/addoncheck-nexus.yml

@@ -8,7 +8,7 @@ jobs:
  runs-on: ubuntu-latest
 
  steps:
- - uses: actions/checkout@v3
+ - uses: actions/checkout@v4
  - name: Set up Python
  uses: actions/setup-python@v4
  with:

.github/workflows/flake8.yml

@@ -8,7 +8,7 @@ jobs:
  runs-on: ubuntu-latest
 
  steps:
- - uses: actions/checkout@v3
+ - uses: actions/checkout@v4
  - name: Set up Python
  uses: actions/setup-python@v4
  with:

.github/workflows/publish.yml

@@ -11,7 +11,7 @@ jobs:
  name: Kodi addon submitter
  steps:
  - name: Checkout
- uses: actions/checkout@v3
+ uses: actions/checkout@v4
  - name: Generate distribution zip and submit to official kodi repository
  id: kodi-addon-submitter
  uses: xbmc/[email protected]