Reject --use-tcore on Tizen <10 and fix transitive includes

Three independent fixes that surfaced when somebody tried
'tools/gn --use-tcore --api-version 6.5':

1. tools/gn now rejects --use-tcore for api_version < 10.0 with a
   clear error message. The tizen-core / tizen-core-imf /
   tizen-core-wl packages are only published in the Tizen 11+
   repository, so building the use_tcore variant against a 6.5/8.0
   sysroot can never succeed.

2. Move '#include <tizen_core_wl.h>' from
   tizen_input_method_context_tcore.h to the .cc. The public
   interface only exposes tizen_core_imf_* types (events go
   through void*), so the .h does not need the wl header. This
   also stops the header from blowing up earlier-than-necessary
   when somebody mis-configures the build.

3. external_texture_surface_vulkan_buffer_dma.cc: add explicit
   '#include <unistd.h>' for close(). The Tizen 11 gcc 14 stdlib
   no longer pulls it in transitively, so the experimental Vulkan
   target failed to compile against sysroot-11.0.

Author: JSUYA

flutter/shell/platform/tizen/external_texture_surface_vulkan_buffer_dma.cc

@@ -3,6 +3,9 @@
 // found in the LICENSE file.
 
 #include "flutter/shell/platform/tizen/external_texture_surface_vulkan_buffer_dma.h"
+
+#include <unistd.h>
+
 #include "flutter/shell/platform/tizen/logger.h"
 
 namespace flutter {

flutter/shell/platform/tizen/tizen_input_method_context_tcore.cc

@@ -4,6 +4,8 @@
 
 #include "tizen_input_method_context_tcore.h"
 
+#include <tizen_core_wl.h>
+
 #include "flutter/shell/platform/tizen/logger.h"
 
 namespace {

flutter/shell/platform/tizen/tizen_input_method_context_tcore.h

@@ -6,7 +6,6 @@
 #define EMBEDDER_TIZEN_INPUT_METHOD_CONTEXT_H_
 
 #include <tizen_core_imf.h>
-#include <tizen_core_wl.h>
 
 #include <functional>
 #include <string>

tools/gn

@@ -120,6 +120,16 @@ def parse_args(args):
 def main():
   args = parse_args(sys.argv)
 
+  if args.use_tcore:
+    try:
+      api_value = float(args.api_version)
+    except ValueError:
+      api_value = 0.0
+    if api_value < 10.0:
+      sys.exit('--use-tcore requires --api-version 10.0 or higher '
+               '(tizen-core packages are only published for Tizen 11+). '
+               'Got --api-version {}.'.format(args.api_version))
+
   root_dir = Path(__file__).parent.parent.resolve()
   gn = root_dir / 'third_party' / 'gn' / 'gn'
   command = [gn, 'gen', '--check', '--export-compile-commands']