fix(eventstore): cleanup org fields on remove (#8946)

# Which Problems Are Solved

When an org is removed, the corresponding fields are not deleted. This
creates issues, such as recreating a new org with the same verified
domain.

# How the Problems Are Solved

Remove the search fields by the org aggregate, instead of just setting
the removed state.

# Additional Changes

- Cleanup migration script that removed current stale fields.

# Additional Context

- Closes https://github.com/zitadel/zitadel/issues/8943
- Related to https://github.com/zitadel/zitadel/pull/8790

---------

Co-authored-by: Silvan <silvan.reusser@gmail.com>

cmd/setup/setup.go

@@ -169,6 +169,7 @@ func Setup(ctx context.Context, config *Config, steps *Steps, masterKey string)
 	steps.s36FillV2Milestones = &FillV3Milestones{dbClient: queryDBClient, eventstore: eventstoreClient}
 	steps.s37Apps7OIDConfigsBackChannelLogoutURI = &Apps7OIDConfigsBackChannelLogoutURI{dbClient: esPusherDBClient}
 	steps.s38BackChannelLogoutNotificationStart = &BackChannelLogoutNotificationStart{dbClient: esPusherDBClient, esClient: eventstoreClient}
+	steps.s39DeleteStaleOrgFields = &DeleteStaleOrgFields{dbClient: esPusherDBClient}
 
 	err = projection.Create(ctx, projectionDBClient, eventstoreClient, config.Projections, nil, nil, nil)
 	logging.OnError(err).Fatal("unable to start projections")
@@ -232,6 +233,7 @@ func Setup(ctx context.Context, config *Config, steps *Steps, masterKey string)
 		steps.s32AddAuthSessionID,
 		steps.s33SMSConfigs3TwilioAddVerifyServiceSid,
 		steps.s37Apps7OIDConfigsBackChannelLogoutURI,
+		steps.s39DeleteStaleOrgFields,
 	} {
 		mustExecuteMigration(ctx, eventstoreClient, step, "migration failed")
 	}