chore(deps): Bump mammoth from 1.9.0 to 1.11.0 in /server

Bumps [mammoth](https://github.com/mwilliamson/mammoth.js) from 1.9.0 to 1.11.0.
- [Release notes](https://github.com/mwilliamson/mammoth.js/releases)
- [Changelog](https://github.com/mwilliamson/mammoth.js/blob/master/NEWS)
- [Commits](mwilliamson/mammoth.js@1.9.0...1.11.0)

---
updated-dependencies:
- dependency-name: mammoth
  dependency-version: 1.11.0
  dependency-type: indirect
...

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

Author: dependabot[bot]