Update unpin_impl ui test to nightly-2022-10-06

Author: dtolnay

tests/ui/unpin_impl.stderr

@@ -5,10 +5,6 @@ error[E0282]: type annotations needed
   | ^^^^^^^^^^^^^^ cannot infer type of the type parameter `Self` declared on the trait `__AmbiguousIfImpl`
   |
   = note: this error originates in the attribute macro `cxx::bridge` (in Nightly builds, run with -Z macro-backtrace for more info)
-help: consider specifying the generic argument
-  |
-1 | #[cxx::bridge]::<_>
-  |               +++++
 
 error[E0283]: type annotations needed
  --> tests/ui/unpin_impl.rs:1:1
@@ -22,7 +18,3 @@ note: multiple `impl`s satisfying `ffi::Opaque: __AmbiguousIfImpl<_>` found
 1 | #[cxx::bridge]
   | ^^^^^^^^^^^^^^
   = note: this error originates in the attribute macro `cxx::bridge` (in Nightly builds, run with -Z macro-backtrace for more info)
-help: consider specifying the generic argument
-  |
-1 | #[cxx::bridge]::<_>
-  |               +++++