Bump actions/checkout from 2.3.4 to 2.4.0

Bumps [actions/checkout](https://github.com/actions/checkout) from 2.3.4 to 2.4.0.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v2.3.4...v2.4.0)

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

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

Author: dependabot[bot]

.github/workflows/distribute-grain.yml

@@ -15,7 +15,7 @@ jobs:
   distribute-grain:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2.3.4
+      - uses: actions/checkout@v2.4.0
 
       - name: Install Packages 🔧
         run: |

.github/workflows/generate-instance.yml

@@ -12,7 +12,7 @@ jobs:
   GenerateCredInstance:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2.3.4
+      - uses: actions/checkout@v2.4.0
         with:
           persist-credentials: false # Required to make github pages deployment work correctly