Support sympy 1.13 - 1.14

[kwabenantim]

Summary

Add support for sympy 1.13 - 1.14

Release notes:

• https://github.com/sympy/sympy/wiki/release-notes-for-1.13.0
• https://github.com/sympy/sympy/wiki/release-notes-for-1.14.0

[kwabenantim]

Relevant sympy 1.13 changes

Float-Integer equality

Float and Integer/Rational no longer compare equal with a == b. From now on Float(2.0) != Integer(2).

This fails as a result: assert_equal('<cn>1</cn>', [sympy.Number(1)])