fixes#25903fixes#25904
`nkExceptBranch` can have variable structure depending on the exception
types and it should handle the last node of the `nkExceptBranch`
* test disable do: block lambda lifting
* fix last test [skip ci]
* deprecate `do:` meaning `do ():` + misc cleanup
closes https://github.com/nim-lang/RFCs/issues/486
* oops
* fix
* no idea what could be causing nimsuggest failure other than this
* ensure ci works