Remove dependency lock file uv.lock. This is a library. (#601)

## About
We think using an `uv.lock` file is only applicable for applications,
and otherwise gives wrong impressions and expectations.

## References
- https://discuss.python.org/t/the-purpose-of-a-lock-file/38756
- https://github.com/orgs/python-poetry/discussions/7847

.gitignore

@@ -8,6 +8,7 @@
 .DS_Store
 coverage.xml
 .coverage*
+*.lock
 
 __pycache__
 tests/__pycache__

CHANGELOG.md

@@ -14,7 +14,6 @@ this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 - CI validation for Python 3.14, 3.14 free-threaded, and PyPy 3.11
 - Marimo notebook mounting docs and example
 - Type annotations for `routes.py`
-- `uv.lock` for reproducible installs
 
 ### Changed