Remove dead reference to angle_spirv_cross_dir

It was removed from ANGLE via https://chromium-review.googlesource.com/c/angle/angle/+/4003675

Bug: angleproject:6081 dawn:2399
Change-Id: I7e471de7be6b1a5895e4857a112cc9b46abf269c
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/174160
Auto-Submit: David Neto <dneto@google.com>
Reviewed-by: Austin Eng <enga@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: David Neto <dneto@google.com>
diff --git a/build_overrides/angle.gni b/build_overrides/angle.gni
index 936e072..95e90c8 100644
--- a/build_overrides/angle.gni
+++ b/build_overrides/angle.gni
@@ -33,7 +33,6 @@
 
 # Paths to ANGLE dependencies in Dawn
 angle_glslang_dir = "//third_party/vulkan-deps/glslang/src"
-angle_spirv_cross_dir = "//third_party/vulkan-deps/spirv-cross/src"
 angle_spirv_headers_dir = "//third_party/vulkan-deps/spirv-headers/src"
 angle_spirv_tools_dir = "//third_party/vulkan-deps/spirv-tools/src"
 angle_vulkan_memory_allocator_dir = "//third_party/vulkan_memory_allocator"