Bump cross-fetch from 3.1.4 to 3.1.5 in /examples/backend-todo (#92)

Bumps [cross-fetch](https://github.com/lquixada/cross-fetch) from 3.1.4 to 3.1.5.
- [Release notes](https://github.com/lquixada/cross-fetch/releases)
- [Commits](lquixada/cross-fetch@v3.1.4...v3.1.5)

---
updated-dependencies:
- dependency-name: cross-fetch
  dependency-type: indirect
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]