Remove use of pkgutil.find_loader #462

Job	Run time
Detect Relevant Path Changes	7s
Build Dash Package	3m 2s
Typing Tests	2m 48s
Run Background & Async Callback Tests (Python ${{ matrix.python-version }})	0s
Table Server Tests (Group ${{ matrix.test-group }})	0s
Table Unit/Lint Tests (Python ${{ matrix.python-version }})	0s
	5m 57s

Provide feedback