Use groupId org.jboss.spec.jakarta.el for the jakarta-6.0 branch

[bstansberry]

Don't differentiate from Eclipse EE4j via a -jbossorg suffix; use a different groupId.

Might as well use the org.jboss.spec.jakarta.el groupId we've been using all along.

BUT:

We'll use the same artifact ids as Eclipse EE4j. No more encapsulating the spec version in the artifact id and forcing user pom updates for every EE release.

[bstansberry]

Resolved in #32