gh-80527: Change support.requires_legacy_unicode_capi() (GH-108438)
The decorator now requires to be called with parenthesis:
@support.requires_legacy_unicode_capi()
instead of:
@support.requires_legacy_unicode_capi
The implementation now only imports _testcapi when the decorator is
called, so "import test.support" no longer imports the _testcapi
extension.
(cherry picked from commit 995f4c48e1)
Co-authored-by: Victor Stinner <vstinner@python.org>