Fix an issue with recent batch fusion update
Summary:
Fix two bugs introduced by D49793793 and D49871774.
1. [framework] We still need to import the model by hardcoding the prefix ".models", because the name of the model is in the format of "dots", not "slashes". Calling `os.path.dirname` will generate empty string.
2. [inductor_speedup] Remove the 2 "_optimus" tests that are already deprecated in the Ads test set.
Reviewed By: aaronenyeshi
Differential Revision: D49889169
fbshipit-source-id: 968aef2d8c217859ce8c89af2142df64d7a0e8a4
