Make safety_checker optional in more pipelines (#1796)
* Make safety_checker optional in more pipelines.
* Remove inappropriate comment in inpaint pipeline.
* InPaint Test: set feature_extractor to None.
* Remove import
* img2img test: set feature_extractor to None.
* inpaint sd2 test: set feature_extractor to None.
Co-authored-by: Suraj Patil <surajp815@gmail.com>
