Fix SwiftShader to use data_deps.

Using deps instead of data_deps was causing some tests to try and
load vk_swiftshader every test execution. Even if the test was not
using Vulkan in ANGLE.

Fixes the TSAN gpu_unittests in Chromium.

Bug: angleproject:3876
Change-Id: I2acbf02ab9aa39632bc252c12e19da28ad90175d
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1815910
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Yuly Novikov <ynovikov@chromium.org>

BUILD.gn

@@ -642,7 +642,7 @@ if (angle_enable_vulkan) {
     }
 
     if (angle_swiftshader) {
-      deps += [
+      data_deps += [
         ":angle_swiftshader_icd",
         "$swiftshader_dir/src/Vulkan:swiftshader_libvulkan",
       ]