fix(team): Prevent null dereference in TeamFactory::createTeam

[seer-by-sentry]

This PR addresses CLIENT-38X, fixing a crash that occurred in TeamFactory::createTeam.

Issue:
TeamFactory::createTeam would cause an EXCEPTION_ACCESS_VIOLATION_READ if createInactiveTeam(name) returned nullptr. This happened when a script (e.g., via ScriptActions::doCreateObject) attempted to create a team using a name for which no TeamPrototype existed.

Root Cause:
createTeam unconditionally called t->setActive() on the Team* t returned by createInactiveTeam. When createInactiveTeam returned nullptr (due to a missing prototype), this resulted in a null dereference.

Fix:
Added a null check for the Team* returned by createInactiveTeam before calling setActive(). If createInactiveTeam returns nullptr, createTeam now safely returns nullptr as well. Callers like ScriptActions::doCreateObject already contain logic to handle a nullptr return from createTeam by logging a warning and returning, thus preventing the crash.

Fixes CLIENT-38X