Bump MU_BASECORE from de31cb5 to 90a7dfa

Bumps [MU_BASECORE](https://github.com/microsoft/mu_basecore) from `de31cb5` to `90a7dfa`.
- [Release notes](https://github.com/microsoft/mu_basecore/releases)
- [Commits](microsoft/mu_basecore@de31cb5...90a7dfa)

---
updated-dependencies:
- dependency-name: MU_BASECORE
  dependency-type: direct:production
...

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