Always use Skia's Vulkan headers when compiling particles module

Previously, doing an official build of Skia with Vulkan and particles
enabled would succeed in compiling all of skia.lib, then fail to find
Vulkan headers for two particle .cpp files (that reach GrVkVulkan.h
via SkSL headers).

Bug: skia:10469
Change-Id: Ia5bdb7df25e7259e43cef3e6ff9719a8c8452022
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/301002
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
diff --git a/BUILD.gn b/BUILD.gn
index a100586..3fa644d 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -1260,6 +1260,10 @@
   ]
 }
 
+config("our_vulkan_headers") {
+  include_dirs = [ "include/third_party/vulkan" ]
+}
+
 # Targets guarded by skia_enable_tools may use //third_party freely.
 if (skia_enable_tools) {
   skia_public_includes = [
@@ -1329,10 +1333,6 @@
     }
   }
 
-  config("our_vulkan_headers") {
-    include_dirs = [ "include/third_party/vulkan" ]
-  }
-
   config("cpp14") {
     if (is_win) {
       cflags_cc = [ "/std:c++14" ]