Update Python dependency locks and plugin catalog checks

[lucarlig]

Summary

• Add a root uv workspace with a single root uv.lock, shared dependency constraints, and exclude-newer = "10 days".
• Remove per-plugin uv.lock files and update CI selection so root Python workspace changes test all plugins.
• Fix wheel installation in CI by resolving the active uv workspace .venv from plugin subdirectories.
• Bump all plugin package versions for release:
  • encoded_exfil_detection: 0.3.4
  • pii_filter: 0.3.4
  • rate_limiter: 0.1.5
  • retry_with_backoff: 0.3.4
  • secrets_detection: 0.3.5
  • url_reputation: 0.3.3

Release Tags

• encoded-exfil-detection-v0.3.4
• pii-filter-v0.3.4
• rate-limiter-v0.1.5
• retry-with-backoff-v0.3.4
• secrets-detection-v0.3.5
• url-reputation-v0.3.3

Testing

• uv lock --check
• cargo check --workspace
• python3 tools/plugin_catalog.py validate .
• python3 -m unittest tests.test_plugin_catalog tests/test_install_built_wheel.py
• NEXTEST_PROFILE=ci make -C plugins/rust/python-package/url_reputation sync ci-build
• Built a release wheel successfully for url_reputation: cpex_url_reputation-0.3.3-cp311-abi3-macosx_11_0_arm64.whl and confirmed it contains package files, plugin-manifest.yaml, url_reputation_rust.abi3.so, dist metadata, and entry points.

[gandhipratik203]

This PR updates the Python dependency locks and CI wiring for the Rust Python plugins, plus bumps the plugin versions. LGTM.