for some reason the rebuild did not use Cython 3, despite the lack of a
BR selecting 0.29 or 3.0. Which was fortuitous because it fails to build
with Cython 3. (see https://github.com/apache/arrow/issues/36857).
Explicitly pinning cython to 0.29 temporarily while awaiting a fix.
Signed-off-by: Kaleb S. KEITHLEY <kkeithle@redhat.com>