Update to scala-xml 2

[kryptt]

More and more sbt plugins are moving to scala-xml 2, for example now I've been blocked from upgrading sbt-scoverage

See:
scoverage/scalac-scoverage-plugin#488
scoverage/sbt-scoverage#439
fthomas/refined#1098

[muuki88]

IIRC there was already an attempt made, but rolled back due to other incompatibilities.

[SethTisue]

I suggest you bite this bullet. It's nearly unheard of for the upgrade to actually cause a problem. The major version number bump frightens people, but the removed things were already deprecated and rarely used anyway.

[SethTisue]

I don't see any previous upgrade attempt other than #1454

[armanbilge]

Well I did the obvious thing and CI seems fine. #1514

[muuki88]

Thanks for all the input 😄 I'll merged the PR and will release next week.

[mkurz]

IMHO next time such an major version bump like from scala-xml 1 to 2 should not be done in a patch release... People start a lot to open issues and ask in chats about the whole scala-xml upgrade mess.
Such changes should be coordinated better next time... Like someone should open pull requests at once in all major plugins and libraries and they all should release new versions within a couple of days....
Also, like I am asking myself, why did get scala-xml bumped to 2 but not scala-parser-combinators? It's just random. We will have the same mess soon with that library...