fix: fix pydantic core import (litestar-org#329)

* fix: import error for pydantic_core imports

This fixes the issue of a MissingDependencyError being raised in the case of pydantic v1 being used. The reason is that
pydantic_core, which is only available in pydantic v2, is being imported. To remedy this, the ImportError when attempting
to import pydantic_core is quitely ignored.

* ci: remove pydantic_core when testing pydantic v1

.github/workflows/ci.yaml

@@ -53,7 +53,7 @@ jobs:
         run: poetry install --no-interaction --extras full
       - name: Install pydantic
         if: matrix.pydantic-version == '1.10'
-        run: source .venv/bin/activate && pip install "pydantic==1.10.10"
+        run: source .venv/bin/activate && pip install "pydantic==1.10.10" && pip uninstall pydantic_core -y
       - name: Set pythonpath
         run: echo "PYTHONPATH=$PWD" >> $GITHUB_ENV
       - name: Test

polyfactory/factories/pydantic_factory.py

@@ -31,17 +31,18 @@
 try:
     from pydantic import VERSION, BaseModel, Json
     from pydantic.fields import FieldInfo
-    from pydantic_core import to_json
 except ImportError as e:
     raise MissingDependencyException("pydantic is not installed") from e
 
 try:
     from pydantic.fields import ModelField  # type: ignore[attr-defined]
-
 except ImportError:
     ModelField = Any
     from pydantic_core import PydanticUndefined as Undefined
 
+with suppress(ImportError):
+    from pydantic_core import to_json
+
 if TYPE_CHECKING:
     from random import Random