📌 pin mypy dependency constraints for PyPy compatibility

Author: techouse

pyproject.toml

@@ -58,7 +58,8 @@ PayPal = "https://paypal.me/ktusar"
 dev = [
     "pytest>=8.1.2",
     "pytest-cov>=5.0.0",
-    "mypy>=1.10.0",
+    "mypy>=1.10.0; platform_python_implementation != \"PyPy\"",
+    "mypy<1.19; platform_python_implementation == \"PyPy\"",
     "toml>=0.10.2",
     "tox",
     "black",

requirements_dev.txt

@@ -1,7 +1,8 @@
 pytest>=8.1.2
 pytest-cov>=5.0.0
-mypy>=1.10.0
+mypy>=1.10.0; platform_python_implementation != "PyPy"
+mypy<1.19; platform_python_implementation == "PyPy"
 toml>=0.10.2
 tox
 black
-isort
+isort