Release Alpakka Kafka 2.1.0-RC1 · akka/alpakka-kafka

Changes

testcontainers kafka 1.15.2 (was 1.15.1) #1345 by @scala-steward
sbt 1.4.9 (was 1.4.5) #1352 by @scala-steward
scala-collection-compat 2.4.3 (was 2.4.2) #1351 by @scala-steward
scala-logging 3.9.3 (was 3.9.2) #1350 by @scala-steward
fix typo in GH action workflow #1346 by @octonato
scala-library 2.12.13 (was 2.12.11) #1342 by @scala-steward
scala-collection-compat 2.4.2 (was 2.2.0) #1344 by @scala-steward
mockito-core 3.8.0 (was 3.7.7) #1341 by @scala-steward
junit-jupiter-api 5.7.1 (was 5.7.0) #1340 by @scala-steward
jupiter-interface, ... 0.9.1 (was 0.8.4) #1339 by @scala-steward
junit 4.13.2 (was 4.13.1) #1338 by @scala-steward
metrics-core 4.1.18 (was 4.1.17) #1337 by @scala-steward
paradox-theme-akka, ... 0.38 (was 0.37) #1335 by @scala-steward
Update scaladex badge #1328 by @seglo
scalapb-runtime 0.10.11 (was 0.10.9) #1320 by @scala-steward
metrics-core 4.1.17 (was 4.1.16) #1321 by @scala-steward
mockito-core 3.7.7 (was 3.7.0) #1324 by @scala-steward
jupiter-interface, ... 0.8.4 (was 0.8.3) #1322 by @scala-steward

Upgrade Akka 2.6.14 and Kafka 2.7.0 #1355 by @seglo
Don't depend on scalatest in testcontainer singleton #1330 by @seglo
Add ProducerResultFactory.multiResult helper for MultiMessage #1319 by @ashendon