ruff: Removes all the ANN type ignores and fixes them

[kingbuzzman]

Lowest risk

[Copilot]

Pull Request Overview

This PR removes all ANN (type annotation) type ignores from the Ruff configuration and adds proper type annotations throughout the codebase to fix the linting violations.

• Adds comprehensive type annotations to function parameters and return types
• Introduces new type aliases _User and _UserModel for better type safety with Django user models
• Updates imports to support proper type checking with TYPE_CHECKING blocks

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
pyproject.toml	Removes ANN-related ignore rules from Ruff configuration
pytest_django/django_compat.py	Adds type aliases for Django user models
pytest_django/fixtures.py	Adds type annotations to fixture functions and classes
pytest_django/plugin.py	Adds type annotations to internal functions
pytest_django/live_server_helper.py	Adds type annotation to __add__ method
pytest_django/asserts.py	Adds comprehensive type annotations to assertion functions
tests/test_fixtures.py	Adds type annotations and updates test function signatures

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