Bump mem0ai from 1.0.11 to 2.0.0b2 in /src/backend

Bumps [mem0ai](https://github.com/mem0ai/mem0) from 1.0.11 to 2.0.0b2.
- [Release notes](https://github.com/mem0ai/mem0/releases)
- [Commits](mem0ai/mem0@v1.0.11...v2.0.0b2)

---
updated-dependencies:
- dependency-name: mem0ai
  dependency-version: 2.0.0b2
  dependency-type: indirect
...

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Author: dependabot[bot]