Manage Anvil via pytest plugin

[YoshihitoAso]

📌 Description

This pull request modernizes and simplifies the project's testing workflow by migrating Anvil process management from shell scripts to Python.

✅ Related Issues

None

🔄 Changes

Testing Workflow Modernization and Anvil Management:

• Replaced the Bash-based Anvil management script (tests/run_anvil_test.sh) with a new Python-based approach using tests/anvil_manager.py and tests/local_anvil_config.py. This enables more robust, cross-platform Anvil lifecycle management directly integrated with pytest via hooks, and removes the need for environment variable juggling in the Makefile and workflow files.
• Updated the GitHub Actions workflow (.github/workflows/pr.yml) and Makefile to use uv run ape test --network ethereum:local:foundry directly, eliminating the custom shell script and simplifying test invocation.

Configuration and Environment Updates:

• Updated ape-config.yaml to:
  • Change the project name.
  • Switch the EVM version from berlin to osaka and enable Solidity's IR-based compilation (via_ir: true).
  • Adjust Foundry/Anvil settings (timeouts, process attempts) for faster and more reliable test runs.
• Refactored config.py to simplify environment variable parsing for configuration values, making the code cleaner and easier to maintain.

📌 Checklist

• I have added tests where necessary.
• I have updated the documentation where necessary.