refactor: unpin protobuf and upgrade in lock (#203)

### TL;DR

Update protobuf and types-protobuf dependencies from pinned versions to
minimum versions.

### What changed?

- Changed `protobuf==5.29.4` to `protobuf>=5.29.5` in pyproject.toml
- Changed `types-protobuf==5.29.1.20250403` to
`types-protobuf>=5.29.1.20250403` in pyproject.toml
- Updated the corresponding entries in uv.lock, where protobuf is now at
version 6.32.1 and types-protobuf is at version 6.30.2.20250822

### How to test?

1. Run the test suite to ensure all functionality works with the updated
dependencies
2. Verify that imports and usage of protobuf-related functionality
continue to work as expected
3. Check for any deprecation warnings that might appear with the newer
versions

### Why make this change?

Using minimum version requirements instead of pinned versions allows for
more flexibility in dependency management and ensures we can get
security updates and bug fixes. The newer versions of protobuf and
types-protobuf likely contain important improvements and security
patches that we want to incorporate.

Author: bcallender

pyproject.toml

@@ -33,8 +33,8 @@ dependencies = [
   "cloudpickle>=3.1.1",
   "jinja2>=3.1.6",
   "scikit-learn>=1.7.1",
-  "protobuf==5.29.4",
-  "types-protobuf==5.29.1.20250403",
+  "protobuf>=5.29.5",
+  "types-protobuf>=5.29.1.20250403",
   "zstandard>=0.23.0",
   "jsonschema>=4.0.0",
   "pymupdf>=1.26.4",