chore(ulsp): remove package registry in ulsp/controller/scip

[zerunz]

Description

This PR finishes the last part to remove the package registry in ulsp/controller/scip and references to it and migrate to the scip-lib registry.

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Refactoring (no functional changes)
• Performance improvement
• Test improvement

Component(s) Affected

• Language Server (ULSP)
• SCIP Generation (Python utilities)
• VS Code/Cursor Extension
• Java Aggregator
• Build System (Bazel)
• Documentation
• Tests

Testing

• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes (bazel test //...)
• I have tested this manually with a real project

Manual Testing Details

Describe how you tested these changes:

• IDE used for testing: cursor
• Project(s) tested against: internal company repo
• Specific features/scenarios verified: Hover, go to definition, find all references

Checklist

• My code follows the existing code style and conventions
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have updated BUILD.bazel files if I added new source files
• My changes generate no new warnings
• Any dependent changes have been merged and published

Screenshots/Logs (if applicable)

Include any relevant screenshots, logs, or output that demonstrates the changes.

Related Issues

Fixes #(issue number)
Closes #(issue number)
Related to #(issue number)

Additional Notes

Any additional information that reviewers should know about this PR.