build(deps): bump codecov/codecov-action from 3 to 4

Bumps [codecov/codecov-action](https://github.com/codecov/codecov-action) from 3 to 4.
- [Release notes](https://github.com/codecov/codecov-action/releases)
- [Changelog](https://github.com/codecov/codecov-action/blob/main/CHANGELOG.md)
- [Commits](https://github.com/codecov/codecov-action/compare/v3...v4)

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

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

.github/workflows/test-backend.yml

@@ -53,7 +53,7 @@ jobs:
     - name: Test
       run: pnpm jest-and-coverage
     - name: Upload Coverage
-      uses: codecov/codecov-action@v3
+      uses: codecov/codecov-action@v4
       with:
         token: ${{ secrets.CODECOV_TOKEN }}
         files: ./packages/backend/coverage/coverage-final.json

.github/workflows/test-frontend.yml

@@ -40,7 +40,7 @@ jobs:
     - name: Test
       run: pnpm --filter frontend test-and-coverage
     - name: Upload Coverage
-      uses: codecov/codecov-action@v3
+      uses: codecov/codecov-action@v4
       with:
         token: ${{ secrets.CODECOV_TOKEN }}
         files: ./packages/frontend/coverage/coverage-final.json

.github/workflows/test-misskey-js.yml

@@ -46,7 +46,7 @@ jobs:
           CI: true
 
       - name: Upload Coverage
-        uses: codecov/codecov-action@v3
+        uses: codecov/codecov-action@v4
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
           files: ./packages/misskey-js/coverage/coverage-final.json