Summary: As discussed and agreed to in {T8707}, turn off the black triangle that's currently drawn by default when windows are drawn with "No Borders"
Test Plan:
- Tested on a new user: no black triangle when KWin's border setting is "No Borders"
- Tested on an existing user who had `DrawSizeGrip=false` in their `breezerc` file: no change
- Tested on an existing user with who had `DrawSizeGrip=false` in their `breezerc` file and then turned it on in System Settings: black triangle appears as expected
- With the black triangle on, reset to default settings: works as expected
Reviewers: #vdg, #breeze, #plasma, abetts, romangg
Reviewed By: #vdg, #plasma, abetts, romangg
Subscribers: hpereiradacosta, romangg, plasma-devel
Tags: #plasma
Maniphest Tasks: T8707
Differential Revision: https://phabricator.kde.org/D13277
Nathaniel Graham
47ca4e814e