build: Remove enum templates

Meson has a handy way to do that without these template files. Let's
just use it

src/gcal-enum-types.c.template

@@ -1,39 +0,0 @@
-/*** BEGIN file-header ***/
-#include "gcal-enum-types.h"
-
-/*** END file-header ***/
-
-/*** BEGIN file-production ***/
-/* enumerations from "@filename@" */
-#include "@filename@"
-
-/*** END file-production ***/
-
-/*** BEGIN value-header ***/
-GType
-@enum_name@_get_type (void)
-{
-	static GType the_type = 0;
-
-	if (the_type == 0)
-	{
-		static const G@Type@Value values[] = {
-/*** END value-header ***/
-
-/*** BEGIN value-production ***/
-			{ @VALUENAME@,
-			  "@VALUENAME@",
-			  "@valuenick@" },
-/*** END value-production ***/
-
-/*** BEGIN value-tail ***/
-			{ 0, NULL, NULL }
-		};
-		the_type = g_@type@_register_static (
-				g_intern_static_string ("@EnumName@"),
-				values);
-	}
-	return the_type;
-}
-
-/*** END value-tail ***/

src/gcal-enum-types.h.template

@@ -1,26 +0,0 @@
-/*** BEGIN file-header ***/
-#ifndef __GCAL_ENUM_TYPES_H__
-#define __GCAL_ENUM_TYPES_H__
-
-#include <glib-object.h>
-
-G_BEGIN_DECLS
-
-/*** END file-header ***/
-
-/*** BEGIN file-production ***/
-/* Enumerations from "@filename@" */
-
-/*** END file-production ***/
-
-/*** BEGIN enumeration-production ***/
-#define GCAL_TYPE_@ENUMSHORT@	(@enum_name@_get_type())
-GType @enum_name@_get_type	(void) G_GNUC_CONST;
-
-/*** END enumeration-production ***/
-
-/*** BEGIN file-tail ***/
-G_END_DECLS
-
-#endif /* __GCAL_ENUM_TYPES_H__ */
-/*** END file-tail ***/

src/meson.build

@@ -16,14 +16,7 @@ gcal_deps = [
   m_dep,
 ]
 
-enum_types = 'gcal-enum-types'
-
-built_sources = gnome.mkenums(
-  enum_types,
-     sources: enum_headers,
-  c_template: enum_types + '.c.template',
-  h_template: enum_types + '.h.template'
-)
+built_sources = gnome.mkenums_simple('gcal-enum-types', sources: enum_headers)
 
 built_sources += gnome.gdbus_codegen(
   'gcal-shell-search-provider-generated',