golang: PyErr_SetExcInfo is now fixed on PyPy

https://bitbucket.org/pypy/pypy/commits/251b47698e8e
https://bitbucket.org/pypy/pypy/issues/3096#comment-54707695

Which in turn fixes recover to clear current exception (see 9e6ff8bd
"golang: Fix recover to clear current exception") for context.

golang/golang_test.py

@@ -1296,7 +1296,7 @@ def test_defer_excchain():
     assert tb[-1].name == "_"
 
 # verify that recover breaks exception chain.
-@mark.xfail('PyPy' in sys.version and sys.version_info >= (3,),
+@mark.xfail('PyPy' in sys.version and sys.version_info >= (3,) and sys.pypy_version_info < (7,3),
                 reason="https://bitbucket.org/pypy/pypy/issues/3096")
 def test_defer_excchain_vs_recover():
     @func