fix(setup): split membership fields migration (#9230)

# Which Problems Are Solved

The membership fields migration timed out in certain cases. It also
tried to migrate instances which were already removed.

# How the Problems Are Solved

Revert the previous fix that combined the repeatable step for multiple
fill triggers. The membeship migration is now single-run as it might
take a lot of time. It is not worth making it repeatable. Instance IDs
of removed instances are skipped.

# Additional Changes

None

# Additional Context

Introduced in https://github.com/zitadel/zitadel/pull/9199

cmd/setup/config.go

@@ -135,6 +135,7 @@ type Steps struct {
 	s44ReplaceCurrentSequencesIndex         *ReplaceCurrentSequencesIndex
 	s45CorrectProjectOwners                 *CorrectProjectOwners
 	s46InitPermissionFunctions              *InitPermissionFunctions
+	s47FillMembershipFields                 *FillMembershipFields
 }
 
 func MustNewSteps(v *viper.Viper) *Steps {