kdePackages.solid: drop merged patch

pkgs/kde/frameworks/solid/default.nix

@@ -1,6 +1,5 @@
 {
   mkKdeDerivation,
-  fetchpatch,
   qttools,
   bison,
   flex,
@@ -12,13 +11,6 @@ mkKdeDerivation {
   patches = [
     # Also search /run/wrappers for mount/umount
     ./fix-search-path.patch
-
-    # Backport fix for mounting removable LUKS devices
-    # FIXME: remove in 6.2
-    (fetchpatch {
-      url = "https://invent.kde.org/frameworks/solid/-/commit/a3b18591ba144fae0cd0cfc087a45c64000d4e51.patch";
-      hash = "sha256-e7+amjOShUSzPb0pAxnAuuh/fbK/YLESqR0co1bs+wg=";
-    })
   ];
 
   extraNativeBuildInputs = [qttools bison flex];