reliability: guard BlueZ base async lifecycles

[geraldo-netto]

Summary

• Add cancellable support to async BlueZ property Set calls in Base.set().
• Track pending property-set cancellables and cancel them when the BlueZ proxy wrapper is destroyed.
• Replace permanent BaseMeta instance caches with per-subclass weak-value caches.
• Remove destroyed instances from the class cache explicitly.
• Add focused tests for cancellable propagation, cancel-on-destroy, weak cache release, per-subclass cache isolation, and destroy cache removal.

Tests

• /usr/bin/python3 -m py_compile blueman/bluez/Base.py test/bluez/test_base.py
• /usr/bin/python3 -m unittest test.bluez.test_base
• ruff check blueman/bluez/Base.py test/bluez/test_base.py
• /usr/bin/python3 -m flake8 --select=E,F,W,C90 --ignore=E402,F403,F405,W504 --max-line-length=120 blueman/bluez/Base.py test/bluez/test_base.py
• PYTHONPATH=stubs pyright --pythonpath /usr/bin/python3 blueman/bluez/Base.py test/bluez/test_base.py

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud