dontInteractiveMoveResize() was added to workaround kwin sending bad
configure events when double clicking mpv to make it fullscreen.

With async geometry updates fixed, dontInteractiveMoveResize() can be
finally removed.

Another reason to remove dontInteractiveMoveResize() is that it can make
kwin crash with a debug build. For example, if you enable resizing
maximized windows in breeze decoration settings and resize a maximized
window, kwin would eventually crash in
the AbstractClient::handleInteractiveMoveResize() function because neither
isInteractiveMove() nor isInteractiveResize() return true.