gnu: kitty: Update to 0.21.2.

There are newer versions of kitty but there are additional requirements.  From
v0.22.0 kitty requires additional Sphinx packages which use node to build
themes.  From v0.27.0 kitty additionally uses Go to build statically compiled,
standalone binaries to use on servers.  This will require more work to
package, if possible at all currently (in the case of node and sphinx themes).

* gnu/packages/patches/kitty-fix-wayland-protocols.patch: New file.
* gnu/local.mk: Add it.
* gnu/packages/terminals.scm (kitty): Update to 0.21.2.
[source]: Use kitty-fix-wayland-protocols.patch.
[native-inputs, inputs]: Remove labels.
[phases]: Use gexps.  Improve style.  Use search-input-file.
Remove trailing #t.
{check}: Respect tests?.

gnu/packages/patches/kitty-fix-wayland-protocols.patch

@@ -0,0 +1,37 @@
+See <https://github.com/kovidgoyal/kitty/issues/6422> for details.
+
+Modified with further fixes from <https://github.com/kovidgoyal/kitty/issues/6422#issuecomment-1622071032>.
+
+From 95d15648fa375bb131ff897f0db03b764dabaf65 Mon Sep 17 00:00:00 2001
+From: Kovid Goyal <kovid@kovidgoyal.net>
+Date: Wed, 5 Jul 2023 10:29:33 +0530
+Subject: [PATCH] Fix not building with wayland-protocols 1.32
+
+Fix #6422
+
+diff --git a/glfw/wl_platform.h b/glfw/wl_platform.h
+index f35b55e94..42c90b1fa 100644
+--- a/glfw/wl_platform.h
++++ b/glfw/wl_platform.h
+@@ -122,6 +122,7 @@ typedef enum WaylandWindowState {
+ 	TOPLEVEL_STATE_TILED_RIGHT = 32,
+ 	TOPLEVEL_STATE_TILED_TOP = 64,
+ 	TOPLEVEL_STATE_TILED_BOTTOM = 128,
++        TOPLEVEL_STATE_SUSPENDED = 256,
+ } WaylandWindowState;
+ 
+ 
+diff --git a/glfw/wl_window.c b/glfw/wl_window.c
+index f7e329609..23868154f 100644
+--- a/glfw/wl_window.c
++++ b/glfw/wl_window.c
+@@ -420,6 +420,9 @@ static void xdgToplevelHandleConfigure(void* data,
+             C(TOPLEVEL_STATE_TILED_RIGHT);
+             C(TOPLEVEL_STATE_TILED_TOP);
+             C(TOPLEVEL_STATE_TILED_BOTTOM);
++#ifdef XDG_TOPLEVEL_STATE_SUSPENDED_SINCE_VERSION
++            C(TOPLEVEL_STATE_SUSPENDED);
++ #endif
+ #undef C
+         }
+     }