fix: fix service getter/setter tasks tracking

[dlech]

Keep a handle to asyncio tasks created for service async property getters and setters to prevent them from being garbage collected before they complete.

[dlech]

Just happened to notice this one while looking at the type hints.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.13%. Comparing base (ea93352) to head (7ad0599).
⚠️ Report is 31 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #550      +/-   ##
==========================================
- Coverage   85.23%   85.13%   -0.10%     
==========================================
  Files          28       28              
  Lines        3426     3431       +5     
  Branches      601      601              
==========================================
+ Hits         2920     2921       +1     
- Misses        313      317       +4     
  Partials      193      193              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[codspeed-hq]

CodSpeed Performance Report

Merging #550 will not alter performance

_{Comparing fix-service-property-tasks (7ad0599) with main (ea93352)¹}

Summary

✅ 6 untouched

Footnotes

1. No successful run was found on main (f368714) during the generation of this report, so ea93352 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩