Update pydantic requirement to 2

Author: Val Brodsky

libs/labelbox/pyproject.toml

@@ -5,7 +5,7 @@ description = "Labelbox Python API"
 authors = [{ name = "Labelbox", email = "[email protected]" }]
 dependencies = [
     "google-api-core>=1.22.1",
-    "pydantic>=1.8",
+    "pydantic>=2.0",
     "python-dateutil>=2.8.2, <2.10.0",
     "requests>=2.22.0",
     "strenum>=0.4.15",