Try updating PDM and relocking (#573)

* Try updating PDM and relocking
* Upgrade ujson

Author: Tinche

.github/workflows/main.yml

@@ -25,7 +25,7 @@ jobs:
           python-version: "${{ matrix.python-version }}"
           allow-python-prereleases: true
           cache: true
-          version: "2.17.3"
+          version: "2.18.1"
 
       - name: "Run Tox"
         run: |