fix: Export PYTHONPATH to GitHub environment for test workflows

.gitea/workflows/test.yml

@@ -46,6 +46,12 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v4
 
+      - name: Export PYTHONPATH
+        shell: bash
+        run: |
+          set -euo pipefail
+          echo "PYTHONPATH=/workspace/allucanget/calminer" >> "$GITHUB_ENV"
+
       # - name: Cache pip dependencies
       #   uses: actions/cache@v4
       #   with: