fix: resolve CI linting and code quality issues

- Remove unused imports across all generator files
- Remove unused variables (spec, url_params, query_params, test_name)
- Fix f-strings without placeholders in auth.py and go.py
- Fix duplicate BASIC auth handling with wrong indentation
- Add missing pytest fixtures (sample_openapi_spec, temp_spec_file, temp_json_spec_file)
- Add missing TemplateRenderError import to generator files

api_testgen/generators/jest.py

@@ -6,8 +6,8 @@ from typing import Any, Dict, List, Optional
 
 from jinja2 import Environment, FileSystemLoader, TemplateSyntaxError, UndefinedError
 
-from ..core import SpecParser, AuthConfig
-from ..core.exceptions import GeneratorError, TemplateRenderError
+from ..core import SpecParser
+from ..core.exceptions import TemplateRenderError
 
 
 class JestGenerator:
@@ -106,7 +106,6 @@ class JestGenerator:
         Returns:
             String containing the test code.
         """
-        test_name = self._generate_test_name(endpoint)
         describe_name = endpoint["summary"] or endpoint["path"]
 
         params = self._generate_params(endpoint)