Bump actions/checkout from 2 to 2.3.4

Bumps [actions/checkout](https://github.com/actions/checkout) from 2 to 2.3.4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v2...v2.3.4)

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/ci.yml

@@ -29,7 +29,7 @@ jobs:
     steps:
       -
         name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v2.3.4
       -
         name: Download files
         shell: bash

.github/workflows/labels.yml

@@ -14,7 +14,7 @@ jobs:
     steps:
       -
         name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v2.3.4
       -
         name: Run Labeler
         uses: crazy-max/ghaction-github-labeler@v3

.github/workflows/test.yml

@@ -16,7 +16,7 @@ jobs:
     steps:
       -
         name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v2.3.4
       -
         name: Validate
         uses: docker/bake-action@v1