applets/status: Do not allow scrolling past 100% volume

The popover menu enables you to go past 100% volume into amplified territory,
however the mark and pressure are there for a reason, you should knowingly
be amplifying the sound.
For some, such as myself, it is still possible to scroll past 100% by
explicitly setting an environmental variable, in this instance just set
BUDGIE_DISRESPECT_LUGHOLES=1