x11-toolkits/wlroots: dedup *_DEPENDS in consumers

LIB_DEPENDS against a port with non-default USE_LDCONFIG can desync
RUN_DEPENDS and BUILD_DEPENDS, leading to incorrectly registered
dependencies when built in a dirty environment.

$ make install -C x11-toolkits/wlroots
$ make install -C x11-wm/hikari
$ pkg info -xr wlroots
wlroots-0.17.1:

hikari-2.3.3_4

wlroots015-0.15.1_2:
$ make run-depends-list -C x11-wm/hikari | fgrep wlroots
/usr/ports/main/x11-toolkits/wlroots015
$ make actual-package-depends -C x11-wm/hikari | fgrep wlroots
"wlroots": {origin: "x11-toolkits/wlroots", version: "0.17.1"}