Revert "Fix type signature of getCaseObjects for 2.11."

This reverts commit 40f775ccf4bb376aceb4dde9a0bb9ad74d2557a8.
Roll back 2.11 support for now.

It's more difficult than I thought to make all the macros work correctly
with both 2.10 and 2.11, so I'm dropping 2.11 support for a bit longer.