SlickProjectionSpec: A Slick grouped projection must restart from previous offset - handler throwing an exception, save after 2

[raboof]

https://github.com/apache/pekko-projection/actions/runs/10040359450/job/27746257858

Notably:

org.h2.jdbc.JdbcSQLIntegrityConstraintViolationException: NULL not allowed for column "CONCATENATED"; SQL statement:
merge into "TEST_MODEL" ("ID","CONCATENATED")  values (?,?) [23502-224]
        at org.h2.message.DbException.getJdbcSQLException(DbException.java:520)

and

[info]   check: last seen offset is 2L The Option on which value was invoked was not defined. (SlickProjectionSpec.scala:953)
[info]   org.scalatest.exceptions.TestFailedException:
[info]   at org.scalatest.OptionValues$OptionValuable.value(OptionValues.scala:114)
[info]   at org.apache.pekko.projection.slick.SlickProjectionSpec.f$proxy17$1$$anonfun$4(SlickProjectionSpec.scala:953)
[info]   at org.scalatest.Assertions.withClue(Assertions.scala:1208)
[info]   at org.scalatest.Assertions.withClue$(Assertions.scala:421)
[info]   at org.apache.pekko.actor.testkit.typed.scaladsl.ScalaTestWithActorTestKit.withClue(ScalaTestWithActorTestKit.scala:41)
[info]   at org.apache.pekko.projection.slick.SlickProjectionSpec.f$proxy17$1(SlickProjectionSpec.scala:955)
[info]   at org.apache.pekko.projection.slick.SlickProjectionSpec.$init$$$anonfun$3$$anonfun$5(SlickProjectionSpec.scala:923)