Draft: make taskswitcher effect enabled by default

on master the task switcher effect is disabled making it inaccessible. this should fix the situation.

draft because after manually enabling it during the testing process I couldn't get it to be disabled again by rebuilding, so I'm not sure this actually fixes it (but fairly sure it does). not sure rn how to restore these settings back to default on my dev setup.

Also unsure how this interacts with a Plasma Desktop install alongside Mobile (does envmanager need to handle this separately or is this covered by having the kwinrc swapped out?)