SolrSpec: should consume and delete beans is flaky

```
[info] SolrSpec:
[info] Pekko Connectors Solr
[info] - should consume and publish SolrInputDocument (757 milliseconds)
[info] - should consume and publish documents as specific type using a bean (719 milliseconds)
[info] - should consume and publish documents as specific type with a binder (710 milliseconds)
[info] - should store documents and pass status to downstream (731 milliseconds)
[info] - should store documents and pass responses with passThrough (Kafka example) (698 milliseconds)
[info] - should consume and delete documents (738 milliseconds)
[info] - should consume and update atomically documents (763 milliseconds)
[info] - should consume and delete beans *** FAILED *** (804 milliseconds)
[info] Vector("Scala Puzzlers", "Scala for Spark in Production") did not equal List() (SolrSpec.scala:506)
[info] Analysis:
[info] Vector1(0: "Scala Puzzlers" -> , 1: "Scala for Spark in Production" -> )
[info] org.scalatest.exceptions.TestFailedException:
[info] at org.scalatest.matchers.MatchersHelper$.indicateFailure(MatchersHelper.scala:397)
[info] at org.scalatest.matchers.should.Matchers$AnyShouldWrapper.shouldEqual(Matchers.scala:7394)
[info] at docs.scaladsl.SolrSpec.$anonfun$new$40(SolrSpec.scala:506)
[info] at org.scalatest.OutcomeOf.outcomeOf(OutcomeOf.scala:85)
[info] at org.scalatest.OutcomeOf.outcomeOf$(OutcomeOf.scala:83)
[info] at org.scalatest.OutcomeOf$.outcomeOf(OutcomeOf.scala:104)
[info] at org.scalatest.Transformer.apply(Transformer.scala:22)
[info] at org.scalatest.Transformer.apply(Transformer.scala:20)
[info] at org.scalatest.wordspec.AnyWordSpecLike$$anon$3.apply(AnyWordSpecLike.scala:1240)
[info] at org.apache.pekko.stream.connectors.testkit.scaladsl.LogCapturing.withFixture(LogCapturing.scala:70)
[info] at org.apache.pekko.stream.connectors.testkit.scaladsl.LogCapturing.withFixture$(LogCapturing.scala:66)
[info] at docs.scaladsl.SolrSpec.withFixture(SolrSpec.scala:46)
[info] at org.scalatest.wordspec.AnyWordSpecLike.invokeWithFixture$1(AnyWordSpecLike.scala:1238)
[info] at org.scalatest.wordspec.AnyWordSpecLike.$anonfun$runTest$1(AnyWordSpecLike.scala:1250)
[info] at org.scalatest.SuperEngine.runTestImpl(Engine.scala:306)
[info] at org.scalatest.wordspec.AnyWordSpecLike.runTest(AnyWordSpecLike.scala:1250)
[info] at org.scalatest.wordspec.AnyWordSpecLike.runTest$(AnyWordSpecLike.scala:1232)
[info] at org.scalatest.wordspec.AnyWordSpec.runTest(AnyWordSpec.scala:1880)
[info] at org.scalatest.wordspec.AnyWordSpecLike.$anonfun$runTests$1(AnyWordSpecLike.scala:1309)
[info] at org.scalatest.SuperEngine.$anonfun$runTestsInBranch$1(Engine.scala:413)
[info] at scala.collection.immutable.List.foreach(List.scala:333)
[info] at org.scalatest.SuperEngine.traverseSubNodes$1(Engine.scala:401)
[info] at org.scalatest.SuperEngine.runTestsInBranch(Engine.scala:390)
[info] at org.scalatest.SuperEngine.$anonfun$runTestsInBranch$1(Engine.scala:427)
[info] at scala.collection.immutable.List.foreach(List.scala:333)
[info] at org.scalatest.SuperEngine.traverseSubNodes$1(Engine.scala:401)
[info] at org.scalatest.SuperEngine.runTestsInBranch(Engine.scala:396)
[info] at org.scalatest.SuperEngine.runTestsImpl(Engine.scala:475)
[info] at org.scalatest.wordspec.AnyWordSpecLike.runTests(AnyWordSpecLike.scala:1309)
[info] at org.scalatest.wordspec.AnyWordSpecLike.runTests$(AnyWordSpecLike.scala:1308)
[info] at org.scalatest.wordspec.AnyWordSpec.runTests(AnyWordSpec.scala:1880)
[info] at org.scalatest.Suite.run(Suite.scala:1114)
[info] at org.scalatest.Suite.run$(Suite.scala:1096)
[info] at org.scalatest.wordspec.AnyWordSpec.org$scalatest$wordspec$AnyWordSpecLike$$super$run(AnyWordSpec.scala:1880)
[info] at org.scalatest.wordspec.AnyWordSpecLike.$anonfun$run$1(AnyWordSpecLike.scala:1354)
[info] at org.scalatest.SuperEngine.runImpl(Engine.scala:535)
[info] at org.scalatest.wordspec.AnyWordSpecLike.run(AnyWordSpecLike.scala:1354)
[info] at org.scalatest.wordspec.AnyWordSpecLike.run$(AnyWordSpecLike.scala:1352)
[info] at docs.scaladsl.SolrSpec.org$scalatest$BeforeAndAfterAll$$super$run(SolrSpec.scala:46)
[info] at org.scalatest.BeforeAndAfterAll.liftedTree1$1(BeforeAndAfterAll.scala:213)
[info] at org.scalatest.BeforeAndAfterAll.run(BeforeAndAfterAll.scala:210)
[info] at org.scalatest.BeforeAndAfterAll.run$(BeforeAndAfterAll.scala:208)
[info] at docs.scaladsl.SolrSpec.run(SolrSpec.scala:46)
[info] at org.scalatest.tools.Framework.org$scalatest$tools$Framework$$runSuite(Framework.scala:321)
[info] at org.scalatest.tools.Framework$ScalaTestTask.execute(Framework.scala:517)
[info] at sbt.TestRunner.runTest$1(TestFramework.scala:153)
[info] at sbt.TestRunner.run(TestFramework.scala:168)
[info] at sbt.TestFramework$$anon$3$$anonfun$$lessinit$greater$1.$anonfun$apply$1(TestFramework.scala:336)
[info] at sbt.TestFramework$.sbt$TestFramework$$withContextLoader(TestFramework.scala:296)
[info] at sbt.TestFramework$$anon$3$$anonfun$$lessinit$greater$1.apply(TestFramework.scala:336)
[info] at sbt.TestFramework$$anon$3$$anonfun$$lessinit$greater$1.apply(TestFramework.scala:336)
[info] at sbt.TestFunction.apply(TestFramework.scala:348)
[info] at sbt.Tests$.processRunnable$1(Tests.scala:475)
[info] at sbt.Tests$.$anonfun$makeSerial$1(Tests.scala:481)
[info] at sbt.std.Transform$$anon$3.$anonfun$apply$2(Transform.scala:47)
[info] at sbt.std.Transform$$anon$4.work(Transform.scala:69)
[info] at sbt.Execute.$anonfun$submit$2(Execute.scala:283)
[info] at sbt.internal.util.ErrorHandling$.wideConvert(ErrorHandling.scala:24)
[info] at sbt.Execute.work(Execute.scala:292)
[info] at sbt.Execute.$anonfun$submit$1(Execute.scala:283)
[info] at sbt.ConcurrentRestrictions$$anon$4.$anonfun$submitValid$1(ConcurrentRestrictions.scala:265)
[info] at sbt.CompletionService$$anon$2.call(CompletionService.scala:65)
[info] at java.util.concurrent.FutureTask.run(FutureTask.java:266)
[info] at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
[info] at java.util.concurrent.FutureTask.run(FutureTask.java:266)
[info] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
[info] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
[info] at java.lang.Thread.run(Thread.java:750)
```

Start with the failing test at SolrSpec.scala:506 and inspect the SolrSpec consume-and-delete-beans case around the reported assertion. Run this test repeatedly to reproduce the flakiness and determine why the expected documents are still present. Done means the test reliably passes and confirms the beans were deleted.

Written by the indexing model from the issue text.