chore(deps): bump openpyxl from 3.1.2 to 3.1.5 in /backend
Bumps [openpyxl](https://openpyxl.readthedocs.io) from 3.1.2 to 3.1.5.
---
updated-dependencies:
- dependency-name: openpyxl
dependency-type: direct:production
update-type: version-update:semver-patch
...
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