fix: class generator produces duplicate imports when regenerating files

[rnetser]

Summary

Fixes the class generator's user_code_parser.py to recognize the new MissingRequiredArgumentError import location (ocp_resources.exceptions) as a template import, preventing duplicate imports when regenerating resource classes with --overwrite.

Problem / Motivation

When regenerating resource files (e.g., class-generator --kind X --overwrite), the parse_user_code_from_file() function checks imports against a hardcoded template_imports set to distinguish template-generated imports from user-added imports. The new correct import pattern from ocp_resources.exceptions import MissingRequiredArgumentError (from the Jinja2 template) is missing from this set, causing the parser to treat it as user-added code and preserve it — resulting in duplicate imports alongside the freshly rendered template imports.

This was observed in PR #2647 where CodeRabbit flagged Ruff F811 (redefinition of unused imports).

Root Cause

class_generator/parsers/user_code_parser.py line 59-65: the template_imports set is missing:

"from ocp_resources.exceptions import MissingRequiredArgumentError"

Requirements

1. Add from ocp_resources.exceptions import MissingRequiredArgumentError to template_imports in user_code_parser.py
2. Update related tests in test_user_code_parser.py
3. Verify all tests pass

Deliverables

• Add from ocp_resources.exceptions import MissingRequiredArgumentError to template_imports in user_code_parser.py
• Update related tests in test_user_code_parser.py
• All tests pass

Notes

This is a one-line fix to the template_imports set, plus corresponding test updates.