build: pin mypy to 1.18.2

mypy depends on librt since 1.19.0 and it fails to build with PyPy 3.10.

Author: link2xt

python/tox.ini

@@ -50,7 +50,7 @@ commands =
 
 [testenv:mypy]
 deps =
- mypy
+ mypy==1.18.2
  typing
  types-setuptools
  types-requests