Bump andstor/file-existence-action from 2 to 3

Bumps [andstor/file-existence-action](https://github.com/andstor/file-existence-action) from 2 to 3.
- [Release notes](https://github.com/andstor/file-existence-action/releases)
- [Commits](andstor/file-existence-action@v2...v3)

---
updated-dependencies:
- dependency-name: andstor/file-existence-action
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

.github/workflows/coverage-base-update.yml

@@ -47,7 +47,7 @@ jobs:
 
  - name: Check file existence
  id: check_files
- uses: andstor/file-existence-action@v2
+ uses: andstor/file-existence-action@v3
  with:
  files: 'base-artifacts/coverage-summary.json, artifacts/coverage-summary.json'
 

.github/workflows/coverage.yml

@@ -67,7 +67,7 @@ jobs:
 
  - name: Check file existence
  id: check_files
- uses: andstor/file-existence-action@v2
+ uses: andstor/file-existence-action@v3
  with:
  files: 'base-artifacts/coverage-summary.json'