Fix pydantic tests (#224)

diff --git a/.github/workflows/third_party.yml b/.github/workflows/third_party.yml
index cde11c1..2e3ee2a 100644
--- a/.github/workflows/third_party.yml
+++ b/.github/workflows/third_party.yml
@@ -54,7 +54,6 @@
         uses: pdm-project/setup-pdm@v3
         with:
           python-version: ${{ matrix.python-version }}
-          cache: true
       - name: Add local version of typing_extensions as a dependency
         run: pdm add ./typing-extensions-latest
       - name: Install pydantic test dependencies