Unused special case for `AnnotatedType` in `RefinedPrinter`

[gsps]

Looking through RefinedPrinter https://github.com/lampepfl/dotty/blob/76b110b5bb029a6607f517304dd2fa9c58547a88/compiler/src/dotty/tools/dotc/printing/RefinedPrinter.scala#L204 I noticed a case that ostensibly overrides the printing of AnnotatedType when testing the pickler (homogenizedView). In reality, that case just computes withoutPos(super.toText(tp)) without returning it and eventually falls through to super.toText(tp). Considering that pickling tests do work, it seems that the special case is not needed anymore, so I suggest we remove it.

[nicolasstucki]

Should test this after #5713 is merged.