Add mailer-deployment to bom

[ggrebert]

The dependency quarkus-mail-deployment is not set in the bom.

Work around used by custom extension:

<dependency>
  <groupId>io.quarkus</groupId>
  <artifactId>quarkus-mailer-deployment</artifactId>
  <version>${quarkus.version}</version>
</dependency>

[quarkus-bot]

Thanks for your pull request!

The title of your pull request does not follow our editorial rules. Could you have a look?

• title should preferably start with an uppercase character (if it makes sense!)

This message is automatically generated by a bot.

[gsmet]

Good catch!

[gsmet]

@aloubyansky we don't have anything in place to catch this sort of thing?

[aloubyansky]

I guess not. We should be doing this kind of check though.