Remove explicit passing of implicit param

[mrdziuban]

In the most recent RC releases of Scala 3 (Scala 3.5.0-RC2, RC2, and RC4) this causes a warning:

-- Error: /path/to/generated/target/scala-3.5.0-RC4/src_managed/main/sbt-scalaxb/scalaxb/scalaxb.scala:727:32
727 |    opt(text ^^ (x => DataRecord(x.node.text)(format)))
    |                      ^^^^^^^^^^^^^^^^^^^^^^^
    |                      Context bounds will map to context parameters.
    |                      A `using` clause is needed to pass explicit arguments to them.
    |                      This code can be rewritten automatically under -rewrite -source 3.4-migration.

[eed3si9n]

Thanks!