chore: fix python warnings

[jamagalhaes]

This PR fixes the following deprecation warnings:

1. plugin_runner/tests/test_application.py

PytestCollectionWarning: cannot collect test class 'TestApplication' because it has a __init__ constructor (from: plugin_runner/tests/test_application.py)
    class TestApplication(Application):

2. plugin_runner/tests/test_plugin_installer.py::test_plugin_installation_from_tarball

DeprecationWarning: pathlib.Path.__enter__() is deprecated and scheduled for removal in Python 3.13; Path objects as a context manager is a no-op
    with download_plugin(attributes["package"]) as plugin_file_path:

3. plugin_runner/tests/test_application.py::test_compute_event_not_targeted

DeprecatedWarning: target is deprecated as of 0.11.0 and will be removed in 1.0.0. Use 'event.target.id' directly instead
    return [self.on_open()] if self.target == self.identifier else []