CMake: Switch status matchers gtest dependency to use iree shim

Adopt changes introduced with 0255a39 to Bazel for CMake. Apologies for not having mentioned that in #409.

Closes https://github.com/google/iree/pull/425

COPYBARA_INTEGRATE_REVIEW=https://github.com/google/iree/pull/425 from marbre:cmake-base-internal-gtest 6bb7b7db2fc566569e3f53449f810f8caf347c2f
PiperOrigin-RevId: 288722920

iree/base/internal/CMakeLists.txt

diff --git a/iree/base/internal/CMakeLists.txt b/iree/base/internal/CMakeLists.txt
index 8f279ab..5c968be 100644
--- a/iree/base/internal/CMakeLists.txt
+++ b/iree/base/internal/CMakeLists.txt
@@ -130,8 +130,8 @@
     "status_matchers.h"
   DEPS
     iree::base::status
+    iree::testing::gtest
     absl::strings
     absl::optional
-    gtest
   TESTONLY
 )