fix: Use correct branch after rename.

This will need to be fixed properly outside of this branch.

Author: BenHenning

.github/workflows/test.yml

@@ -33,7 +33,7 @@ jobs:
         uses: actions/checkout@v4
         with:
           repository: 'google/blockly'
-          ref: 'develop'
+          ref: 'main'
           path: core-blockly
 
       - name: Use Node.js 20.x