runtime: don't check for String/Error methods in printany

runtime: don't check for String/Error methods in printany

They have either already been called by preprintpanics, or they can
not be called safely because of the various conditions checked at the
start of gopanic.

Fixes #24059

Change-Id: I4a6233d12c9f7aaaee72f343257ea108bae79241
Reviewed-on: https://go-review.googlesource.com/96755
Reviewed-by: Austin Clements <austin@google.com>