This commit fixes a test exercising complex numbers creation, working
around a deprecation introduced in CPython 3.14.
Creating complex numbers using a complex number as the real part in the
constructor is deprecated in CPython 3.14, but that construction method
is still supported by MicroPython and covered by tests. To work around
this, the specific constructor is extracted into its own test, providing
an expected output file recorded using CPython 3.11.
Signed-off-by: Alessandro Gatti <a.gatti@frob.it>
