ci: Use datajoint-python master branch for docs build

Now that pre/v2.1 has been merged into master, build docs from master.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: dimitri-yatsenko

.github/workflows/development.yml

@@ -17,7 +17,7 @@ jobs:
         uses: actions/checkout@v2
         with:
           repository: datajoint/datajoint-python
-          ref: pre/v2.1
+          ref: master
           path: datajoint-python
       - name: Compile docs static artifacts
         run: |