fix issue MapType as a type hint for schema 55900

[deepanshu36]

Why are the changes needed?

I have added a one line change to let spark know that u can have MapType also as a schema argument, earlier it did not consider schema argument in the file and niether imported it, i have added those change in the latest commit. please have a look

[deepanshu36]

please have a look at the changes

[deepanshu36]

Problem

from_json accepts MapType as a valid schema at runtime and
is even shown in the official documentation. However, the type
stub does not include MapType in the Union, causing type
checkers to raise an error.

Fixes #55900

Changes

• Added MapType to the schema parameter type hint in from_json
• Added MapType to the imports in the type stub