SmallRye Metrics 2.4.0

This release implements MicroProfile Metrics 2.3, including the optional REST metrics.

• For a changelog of the 2.3 specification, see 2.3 spec changelog
• For a changelog of the SmallRye Metrics side, see 2.4.0 milestone

To depend on this release using Maven:

<dependency>
  <groupId>io.smallrye</groupId>
  <artifactId>smallrye-metrics</artifactId>
  <version>2.4.0</version>
</dependency>

Enjoy!