Dhruv Manilawala
38f873ba52
Remove flatten to improve deserialization error messages (#15414)
## Summary
Closes: #9719
## Test Plan
**Before:**
```
ruff failed
Cause: Failed to parse /Users/dhruv/playground/ruff/pyproject.toml
Cause: TOML parse error at line 22, column 1
|
22 | [tool.ruff.lint]
| ^^^^^^^^^^^^^^^^
invalid type: string "false", expected a boolean
```
**After:**
```
ruff failed
Cause: Failed to parse /Users/dhruv/playground/ruff/pyproject.toml
Cause: TOML parse error at line 27, column 20
|
27 | mypy-init-return = "false"
| ^^^^^^^
invalid type: string "false", expected a boolean
```