fix: Add missing Pydantic dev-dep (docs group)

Author: pawamoy

project/pyproject.toml.jinja

@@ -111,6 +111,7 @@ ci = [
     "mkdocs-minify-plugin>=0.8",
     "mkdocs-section-index>=0.3",
     "mkdocstrings[python]>=0.29",
+    "pydantic>=2.10",
     # YORE: EOL 3.10: Remove line.
     "tomli>=2.0; python_version < '3.11'",
 ]