games-emulation/dolphin: use system version of dev-libs/libfmt

Follow the update pntroduced in
dolphin-emu/dolphin#8198

Reported-by: Samuel BAUER
Package-Manager: Portage-2.3.94, Repoman-2.3.21
Signed-off-by: Sergei Trofimovich <[email protected]>

Author: Sergei Trofimovich

games-emulation/dolphin/dolphin-9999.ebuild

@@ -26,6 +26,7 @@ IUSE="alsa bluetooth discord-presence doc +evdev ffmpeg libav log lto profile pu
 
 RDEPEND="
 	dev-libs/hidapi:0=
+	dev-libs/libfmt:0=
 	dev-libs/lzo:2=
 	dev-libs/pugixml:0=
 	media-libs/libpng:0=
@@ -83,7 +84,6 @@ src_prepare() {
 		FreeSurround
 		cpp-optparse
 		# no support for for using system library
-		fmt
 		glslang
 		imgui
 		# FIXME: xxhash can't be found by cmake