net-im/iamb: inherit xdg for properly doing pkg_post functions

Instead of the previous version where the ebuild was inheriting
xdg-utils eclass and pkg_post(inst|rm) was manually being set, inherit
the xdg eclass which actually sets the proper logic for
pkg_post(inst|rm) functions.

As recommended by
8f67d18398 (r178222407)

Signed-off-by: ingenarel (NeoJesus) <ingenarel_neojesus@disroot.org>

net-im/iamb/iamb-0.0.11.ebuild

@@ -723,7 +723,7 @@ CRATES="
 	zvariant_utils@1.0.1
 "
 
-inherit cargo desktop xdg-utils
+inherit cargo desktop xdg
 
 DESCRIPTION="A Matrix chat client that uses Vim keybindings"
 HOMEPAGE="https://iamb.chat/"
@@ -769,13 +769,3 @@ src_install() {
 
 	cargo_src_install
 }
-
-pkg_postinst() {
-	xdg_desktop_database_update
-	xdg_icon_cache_update
-}
-
-pkg_postrm() {
-	xdg_desktop_database_update
-	xdg_icon_cache_update
-}