Remove deprecated code for Micronaut 4

[sdelamo]

Per module tasks:

• [ ] Create a Mayor version branch
• [ ] Target that branch to 4.0.x by setting githubCoreBranch
• [ ] Remove deprecated code in that branch.
• [ ] Set micronaut version to 4.0.0-SNAPSHOT
• [ ] Set micronautTest version to 3.5.0
• [ ] Add snapshot repos where necessary (this might include dependencyResolutionManagement in settings.gradle, and make sure docs and testCodeCoverageReport tasks also work)
• [ ] use buildSrc scripts to expose snapshot repos to avoid unnecessary duplication

---

• [x] Micronaut TOML
• [x] Micronaut Elastic Search
• [x] Micronaut JMX
• [x] Micronaut Micrometer
• [x] Micronaut GraphQL
• [x] Micronaut GRPC
• [x] Micronaut Jackson XML
• [x] Micronaut JAX-RS
• [x] Micronaut OpenAPI
• [x] Micronaut Problem-JSON
• [x] Micronaut Serialization
• [x] Micronaut Microstream
• [x] Micronaut Servlet
• [x] Micronaut Spring
• [ ] Micronaut AOT
• [ ] Micronaut Gradle Plugin
• [ ] Micronaut Maven Plugin
• [x] Micronaut AWS
• [x] Micronaut Azure
• [x] Micronaut Discovery Client
• [x] Micronaut GCP
• [ ] Micronaut Kubernets
• [x] Micronaut Oracle Cloud
• [x] Micronaut Tracing
• [ ] Micronaut Data
• [x] Micronaut Cassandra
• [x] Micronaut MongoDB
• [x] Micronaut Neo4j
• [ ] Micronaut R2DBC
• [x] Micronaut Redis
• [ ] Micronaut SQL
• [x] Micronaut Flyway
• [x] Micronaut Liquibase
• [x] Micronaut Groovy
• [x] Micronaut Kotlin
• [x] Micronuat JMS
• [x] Micronaut Kafka
• [x] Micronaut MQTT
• [x] Micronaut NATS
• [x] Micronaut RabbitMQ
• [x] Micronaut ACME
• [x] Micronaut Cache
• [x] Micronaut Email
• [x] Micronaut Hibernate Validator
• [ ] Micronaut ignite
• [x] Micronaut Picocli
• [x] Micronaut Security
• [x] Micronaut Test
• [x] Micronaut Reactor
• [x] Micronaut RxJava2
• [x] Micronaut RxJava3
• [x] Micronaut Multi-tenancy
• [x] Micronaut RSS
• [x] Micronaut TOML
• [x] Micronaut Views

[wetted]

See https://github.com/micronaut-projects/micronaut-neo4j/issues/269

Micronaut-Neo4j is blocked by a Java17 compatible version (5.x) of neo4jj/neo4j-java-driver

[wetted]

@melix @alvarosanchez will handle the micronaut-gradle-plugin and micronaut-maven-plugin separately