Show all non-critical typing errors as warnings

In VSCode's settings.json, I enabled PyLance's type checking:

"python.analysis.typeCheckingMode": "basic"

This shows all typing issues as errors (underlined in red), even when code is valid Python and will run with no issue.

For example, the following code is valid Python, and works:

if 4 % 2 == 0:
    a = 3
print(a)

...but PyLance shows an error because of the case where a is unbound:

I want to only mark as "errors" the actual syntax errors that will be rejected by Python, and mark everything else as warnings. I can do it for one category with:

"python.analysis.diagnosticSeverityOverrides": {
    "reportGeneralTypeIssues": "warning"
}

How can I do that for all such errors?

Sorry, but I am afraid you only can override the diagnostic severity explicitly one by one.

Such as set "reportUnboundVariable": "warning", to change the error to warning which you have metioned in the above.

But, there is no way to change all of them one time.