Duplicate supports_ref_counts

[mattip]

A second implementation of the supports_ref_counts function in support.py was added in PR #390, I think this was supposed to be named something related to vectorcall?

hpy/test/support.py

Lines 498 to 505 in f611473

	def supports_refcounts(self):
	""" Returns True if the underlying Python implementation supports
	the vectorcall protocol.
	By default, this returns True for Python version 3.8+ on all
	implementations.
	"""
	return sys.version_info >= (3, 8)

@fangerer

[fangerer]

True, that was a mistake. I'll fix it.

[mattip]

Closed by #455