feat: add pytest to python-toolchain v3

Author: sigma

packages/python-toolchain/data.json

@@ -1,5 +1,11 @@
 {
-  "_meta": { "default": "2" },
+  "_meta": { "default": "3" },
+  "3": {
+    "python": "3.13.12",
+    "uv": "0.11.6",
+    "ruff": "0.15.6",
+    "pytest": "9.0.3"
+  },
   "1": {
     "python": "3.13.12",
     "uv": "0.10.9",