* gnu/packages/bioinformatics.scm (cnvkit): Update to 0.9.12.
[build-system]: Switch to pyproject.
[native-inputs]: Add python-setuptools, python-wheel.
Change-Id: Ia48f681ac2c45872c92214d685819579a40eae7a
Signed-off-by: Steve George <steve@futurile.net>