Revert "mw.loader: Fix regression that caused CSS load after scripts."

Broke master tests since it causes a JSDuck issue. See bug 47018.

This reverts commit be5f73b595b8fef0697bf83e9ebd13e85756c099

Change-Id: I2d945b7ffb7cfbcc5024a1c3bdcf0c9506b0cf76