When sharing a monitor with a HDMI switch, repeatedly switching the HDMI source among connected machines will lead to a blank screen without output signals for a box running a sway compositor. The issue can be observed on AMD GPUs (Rx 6600 / Rx 460). Reproducible: Always Steps to Reproduce: 1. Compiles the sys-auth/seatd with the USE flags "server" and "builtin" disabled. 2. Shares the monitor with a HDMI switch (N sources connected to multiple machines, 1 output connected to the monitor) 3. Switching the HDMI source repeatedly. Actual Results: Blank screen, the monitor shows its debug message "no HDMI output". Expected Results: Working HDMI output. After add the builtin/server USE flag to sys-auth/seatd, the bug seems to be fixed. The ebuild should be updated to enforce the dependency of related USE flags.
