Revert "chore: Deprecate same_process_as_parent (#4244)" (#4290)

This reverts commit e05ed0a.

`same_process_as_parent` is `True` by default, so we actually don't have
a way of detecting whether this was set explicitly by the user or not.

Removing the deprecation altogether -- no one's using this.

Closes #4289

Author: sentrivana

sentry_sdk/tracing.py

@@ -323,13 +323,6 @@ def __init__(
 
             self.scope = self.scope or hub.scope
 
-        if same_process_as_parent is not None:
-            warnings.warn(
-                "The `same_process_as_parent` parameter is deprecated.",
-                DeprecationWarning,
-                stacklevel=2,
-            )
-
         if start_timestamp is None:
             start_timestamp = datetime.now(timezone.utc)
         elif isinstance(start_timestamp, float):