chore: bump version to 1.1.19 (#284)

Bumps the version in `pyproject.toml` from 1.1.18 to 1.1.19 for the next
release.

This merges last, after the PRs in the current integration hub have
landed on `master`.

## Test plan

- [x] Editable install in a fresh venv (Python 3.10):
`spatialmath.__version__ == "1.1.19"`
- [x] Full test suite: 473 passed, 3 skipped

Co-authored-by: Copilot <198982749+Copilot@users.noreply.github.com>

Author: taughz

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "spatialmath-python"
-version = "1.1.18"
+version = "1.1.19"
 authors = [
   { name="Peter Corke", email="rvc@petercorke.com" },
 ]