Re-disable rls packaging for 1.19

[brson]

Currently on the 1.19 branch rls is packaged for standalone installers and also (I think) for rustup.

Unfortunately there is still debate about the the story we want to tell here wrt the stability of the RLS, so it's not happening for 1.19

Revert the PR that added it to the installers and make sure it's not packaged for rustup. Since 1.19 branches soon this will likely need to be backported.

cc @alexcrichton @nrc

[brson]

It looks like this was disabled in this backport.

[brson]

AFAIK there is no movement to get rls stable for 1.20 so we may have to do it again....

[brson]

I'm going to claim this is done.