[Python] Fix async await in branches and cast in closures

[dbrattli]

Summary

• Fix missing await in async functions when return is inside if/else, match, try/with, or loops — wrapReturnWithAwait is now recursive
• Fix UnboundLocalError caused by cast() reassigning variables inside closures — disabled makeCastStatement since isinstance() already narrows for Pyright

[github-actions]

Python Type Checking Results (Pyright)

Metric	Value
Total errors	13
Files with errors	2
Excluded files	2
New errors	✅ No

Excluded files with errors (2 files)

These files have known type errors and are excluded from CI. Remove from pyrightconfig.ci.json as errors are fixed.

File	Errors	Status
temp/tests/Python/test_applicative.py	12	Excluded
temp/tests/Python/fable_modules/thoth_json_python/encode.py	1	Excluded