Change the numpy dependency to match how the nitypes repo declares it

[mikeprosserni]

What does this Pull Request accomplish?

This PR changes how the numpy dependency is declared in pyproject.toml, to match how it is done in the nitypes repo. By making the dependency version logic match, this allows nipanel to use a newer, better version of numpy, as well as the latest version of nitypes.

Why should this Pull Request be merged?

This is needed so we can uptake the latest version of nitypes.

What testing has been done?

poetry lock
poetry install --with examples
poetry run pytest ./tests/unit

[github-actions]

Test Results

   10 files  ±0     10 suites  ±0   25s ⏱️ -1s
  190 tests ±0    190 ✅ ±0  0 💤 ±0  0 ❌ ±0 
1 850 runs  ±0  1 850 ✅ ±0  0 💤 ±0  0 ❌ ±0 

Results for commit 3395544. ± Comparison against base commit 983fe9d.