pip prod(deps): update pooch requirement from <1.8.3 to <1.9.1

Updates the requirements on [pooch](https://github.com/fatiando/pooch) to permit the latest version.
- [Release notes](https://github.com/fatiando/pooch/releases)
- [Changelog](https://github.com/fatiando/pooch/blob/main/doc/changes.rst)
- [Commits](fatiando/pooch@v0.1...v1.9.0)

---
updated-dependencies:
- dependency-name: pooch
  dependency-version: 1.9.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

requirements-testing.txt

@@ -4,7 +4,7 @@ pytest-cov<7.0.1
 flake8-pyproject>=1.2.3,<1.2.5
 nbval<0.11.1
 scipy<1.15.4
-pooch<1.8.3
+pooch<1.9.1
 click<9.0
 cloudpickle<3.1.3
 ipympl<0.10.1