Don't expect a writeModelCount for ThingDeleteModel

* In case of a retry, the entry could already be deleted and therefore
  the deleted count is 0 but the expected writeModelCount is 1.
  This will lead to an infinite loop

Signed-off-by: Yannic Klem <Yannic.Klem@bosch.io>

thingsearch/service/src/main/java/org/eclipse/ditto/thingsearch/service/persistence/write/streaming/BulkWriteResultAckFlow.java

@@ -30,6 +30,7 @@
 import org.eclipse.ditto.thingsearch.api.commands.sudo.UpdateThingResponse;
 import org.eclipse.ditto.thingsearch.service.persistence.write.model.AbstractWriteModel;
 import org.eclipse.ditto.thingsearch.service.persistence.write.model.Metadata;
+import org.eclipse.ditto.thingsearch.service.persistence.write.model.ThingDeleteModel;
 import org.eclipse.ditto.thingsearch.service.persistence.write.model.WriteResultAndErrors;
 
 import com.mongodb.ErrorCategory;
@@ -199,9 +200,11 @@ private static ConsistencyCheckResult checkForConsistencyError(final WriteResult
 
     private static boolean areUpdatesMissing(final WriteResultAndErrors resultAndErrors) {
         final var result = resultAndErrors.getBulkWriteResult();
-        final int writeModelCount = resultAndErrors.getWriteModels().size();
-        final int matchedCount = result.getMatchedCount();
-        final int upsertCount = result.getUpserts().size();
+        final long writeModelCount = resultAndErrors.getWriteModels().stream()
+                .filter(writeModel -> !(writeModel instanceof ThingDeleteModel))
+                .count();
+        final long matchedCount = result.getMatchedCount();
+        final long upsertCount = result.getUpserts().size();
         return matchedCount + upsertCount < writeModelCount;
     }