Build against wlroots git

This allows me to test if things work on more recent wlroots than 0.16

Some lose ends to finish but let's make this a draft MR so i can

• fix CI (we have all the deps in Debian)
• get notified when there's merge conflicts

TODO

• use wlr_damage_ring (#327 (closed)) (!491 (merged))
• use wlr_output_state (#328 (closed)) (!492 (merged))
• use wlr_output_configure_primary_swapchain (wloots commit fef8ab22e3bc8e073b63ec2cc612d91d8b81a9f6)
• use wlr_render_pass (see sway commit 029b99b4829148ef3e899f21bba4fe2a1d4d0db9)
• drop usage of wlr_output_commit in favour of wlr_output_commit_state (see sway f3b8c9feeed9f79fc8f06e7f1dcfaadde522ce90) so we use a detached output state for page flips too (see #344 (closed))
• drop wlr_idle (after !idle) is merged so we can forward to wlroots git later than a289f812d62059d5aac92cbd374dcb7b03bb08a6 (!490 (merged))
• hide xwayland-shell-v1 from clients
• support security-context v1
• support fractional-scale-v1 (https://gitlab.freedesktop.org/wlroots/wlroots/-/merge_requests/3511 (See #345 (closed))
• Add Breaks on phosh that don't support ext-idle-notify-v1 (will do once there's a release)
• Add Breaks on phog that don't support ext-idle-notify-v1 (will do once there's a release)

Most of the above can be follow ups but keeping them here so we can have issues once this is merged.