Remove obsolete bindgen 0.71 workaround

Summary: This reverts my folly workaround from {D80186965} because the bindgen fix [bindgen#3278](rust-lang/rust-bindgen#3278) has made it into fbsource's version of bindgen since {D81525185}.

Reviewed By: diliop

Differential Revision: D81525186

fbshipit-source-id: 3d36156e1f913f050f9af26a1938b65025aa8779

Author: David Tolnay

folly/rust/iobuf/BUCK

@@ -48,12 +48,6 @@ rust_bindgen_library(
         "facebook::rust::.*",
     ],
     blocklist_types = [
-        # Work around incorrect detection of nested name specifier. T234253370
-        # Bindgen needs to be fixed to understand the new AST representation.
-        # https://github.com/llvm/llvm-project/pull/147835
-        "folly::IOBuf_Iterator",
-        "folly::IOBuf_iterator",
-        "folly::IOBuf_const_iterator",
         # These seems to come from type_traits / make_signed via fbvector
         "folly::fbvector.*",
         "__type",