build: Bump filament/upgrade from 3.1.47 to 3.2.6

Bumps [filament/upgrade](https://github.com/filamentphp/upgrade) from 3.1.47 to 3.2.6.
- [Commits](filamentphp/upgrade@v3.1.47...v3.2.6)

---
updated-dependencies:
- dependency-name: filament/upgrade
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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