Embeddables that are nullable but not object result in error

[Langstra]

Describe the bug
Having an embeddable defined like this @Embedded(() => Profile, { nullable: true }) and then assigning is null results in an error. This behaviour seems to be since v5.5, before this went fine.

Stack trace

Cannot read property 'replace' of undefined
TypeError: Cannot read property 'replace' of undefined
  at BetterSqlitePlatform.quoteIdentifier (/mikro-orm/packages/core/src/platforms/Platform.ts:347:26)
  at /mikro-orm/packages/knex/src/AbstractSqlDriver.ts:329:68
  at Array.map (<anonymous>)
  at BetterSqliteDriver.nativeInsertMany (/mikro-orm/packages/knex/src/AbstractSqlDriver.ts:329:45)
  at ChangeSetPersister.persistNewEntity (/mikro-orm/packages/core/src/unit-of-work/ChangeSetPersister.ts:107:35)
  at ChangeSetPersister.executeInserts (/mikro-orm/packages/core/src/unit-of-work/ChangeSetPersister.ts:38:18)
  at ChangeSetPersister.runForEachSchema (/mikro-orm/packages/core/src/unit-of-work/ChangeSetPersister.ts:86:42)
  at ChangeSetPersister.executeInserts (/mikro-orm/packages/core/src/unit-of-work/ChangeSetPersister.ts:27:19)
  at UnitOfWork.commitCreateChangeSets (/mikro-orm/packages/core/src/unit-of-work/UnitOfWork.ts:881:35)
  at UnitOfWork.persistToDatabase (/mikro-orm/packages/core/src/unit-of-work/UnitOfWork.ts:819:7)
  at BetterSqliteConnection.transactional (/mikro-orm/packages/knex/src/AbstractSqlConnection.ts:51:19)
  at UnitOfWork.doCommit (/mikro-orm/packages/core/src/unit-of-work/UnitOfWork.ts:362:9)
  at UnitOfWork.commit (/mikro-orm/packages/core/src/unit-of-work/UnitOfWork.ts:330:7)
  at SqlEntityManager.flush (/mikro-orm/packages/core/src/EntityManager.ts:981:5)
  at Object.<anonymous> (/mikro-orm/tests/issues/GH9999.test.ts:50:3)

To Reproduce
Steps to reproduce the behavior:

1. Checkout the PR #3771
2. Run the test
3. When adding {object: true} to the Embedded it would work

Expected behavior
All columns in the table belonging to the Embeddable should get the null value. Or if you'd consider this the correct behaviour a better error message should be displayed indicating the problem.

Additional context
In v5.4.2 (bf35754) this did work

Versions

Dependency	Version
node	?
typescript	?
mikro-orm	5.5.x
your-driver	?