Remove duplicate imports in chromevoxclassic build file

This change does not affect the number of tests that pass (there are
30 failing tests before and after).

AX-Relnotes: n/a.
Bug: None
Change-Id: I88dc959ab9f76cd9b264ba5c1241a53735046556
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3402603
Reviewed-by: Akihiro Ota <akihiroota@chromium.org>
Commit-Queue: Anastasia Helfinstein <anastasi@google.com>
Cr-Commit-Position: refs/heads/main@{#961554}

ui/accessibility/extensions/chromevoxclassic/BUILD.gn

@@ -9,8 +9,6 @@ import(
     "//chrome/browser/resources/chromeos/accessibility/strings/accessibility_strings.gni")
 import("//chrome/common/features.gni")
 import("//chrome/test/base/js2gtest.gni")
-import("//chrome/test/base/js2gtest.gni")
-import("//testing/test.gni")
 import("//testing/test.gni")
 import("//third_party/closure_compiler/compile_js.gni")
 import("//third_party/liblouis/liblouis_library.gni")