[FEATURE]Unable to use user_memory with custom provider.

[Saicheg]

Feature Area

Core functionality

Is your feature request related to a an existing bug? Please link it here.

crewAI/src/crewai/memory/contextual/contextual_memory.py

Line 38 in 8df1042

if self.memory_provider == "mem0":

Currently there is a hard-coded condition, checking if provider of mem0 is assigned when using user memory.
Which sounds very limiting. I would love to use any provider for user memories similar to other types of memory.

Describe the solution you'd like

    user_memory = UserMemory(
        storage=CustomLTMSQLiteStorage(
            db_path="/my_crew1/user_memory_storage.db",
            user_id=self.user_id
        )

),

Describe alternatives you've considered

No response

Additional context

No response

Willingness to Contribute

Yes, I'd be happy to submit a pull request