x11-drivers/nvidia-drivers: re-add comment about vulkan icd

There used to be one in older ebuilds and it wasn't meant
to be lost as reason for skipping with -X can look confusing
without knowing that it relies on libGLX currently.

Signed-off-by: Ionen Wolkens <ionen@gentoo.org>

x11-drivers/nvidia-drivers/nvidia-drivers-390.147.ebuild

@@ -219,6 +219,7 @@ src_install() {
 	)
 
 	local skip_files=(
+		# nvidia_icd(vulkan): skip with -X too as it uses libGLX_nvidia
 		$(usex X '' '
 			libGLX_nvidia libglx
 			libnvidia-ifr

x11-drivers/nvidia-drivers/nvidia-drivers-470.103.01.ebuild

@@ -211,6 +211,7 @@ src_install() {
 	)
 
 	local skip_files=(
+		# nvidia_icd/layers(vulkan): skip with -X too as it uses libGLX_nvidia
 		$(usex X '' '
 			libGLX_nvidia libglxserver_nvidia
 			libnvidia-ifr

x11-drivers/nvidia-drivers/nvidia-drivers-470.62.22.ebuild

@@ -212,6 +212,7 @@ src_install() {
 	)
 
 	local skip_files=(
+		# nvidia_icd/layers(vulkan): skip with -X too as it uses libGLX_nvidia
 		$(usex X '' '
 			libGLX_nvidia libglxserver_nvidia
 			libnvidia-ifr

x11-drivers/nvidia-drivers/nvidia-drivers-510.54.ebuild

@@ -217,6 +217,7 @@ src_install() {
 	)
 
 	local skip_files=(
+		# nvidia_icd/layers(vulkan): skip with -X too as it uses libGLX_nvidia
 		$(usev !X "
 			libGLX_nvidia libglxserver_nvidia
 			nvidia_icd.json nvidia_layers.json")