build(deps): bump actions/checkout from 6 to 7

Bumps [actions/checkout](https://github.com/actions/checkout) from 6 to 7.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v6...v7)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/build-and-push.yml

@@ -54,11 +54,11 @@ jobs:
           large-packages: true
           docker-images: true
           swap-storage: true
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
         with:
           repository: "Chatterino/chatterino2"
           submodules: recursive
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
         with:
           path: "chatterino-docker"
 
@@ -121,7 +121,7 @@ jobs:
     steps:
       - name: Lowercase Repo Owner in IMAGE_NAME env var
         run: echo "IMAGE_NAME=${IMAGE_NAME,,}" >> "${GITHUB_ENV}"
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
         with:
           path: "chatterino-docker"