Bump submods/amrex from 63e03ea to f8d7483

Bumps [submods/amrex](https://github.com/AMReX-Codes/amrex) from `63e03ea` to `f8d7483`.
- [Release notes](https://github.com/AMReX-Codes/amrex/releases)
- [Commits](AMReX-Codes/amrex@63e03ea...f8d7483)

---
updated-dependencies:
- dependency-name: submods/amrex
  dependency-type: direct:production
...

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