CI: Latest sympy disables typehinting because "[adding py.typed to sy…

…mpy] was a mistake to add it before adding the corresponding type hints." -- sympy/sympy#22337 . So we disable it on sympy as well. Check also this for progress in adding proper typehinting to sympy: sympy/sympy#25103

.mypy.ini

@@ -0,0 +1,14 @@
+[mypy]
+disallow_untyped_calls = False
+disallow_untyped_defs = True
+disallow_incomplete_defs = True
+check_untyped_defs = True
+disallow_untyped_decorators = True
+no_implicit_optional = True
+warn_redundant_casts = True
+warn_unused_ignores = True
+warn_return_any = True
+strict_equality = True
+
+[mypy-sympy.*]
+ignore_missing_imports = True