[runtimes] Remove dependencies on cxx_experimental for test-suite installs (#171678)

This patch removes explicit dependencies on cxx_experimental for
installations that are local to the test suite. Such dependencies
are not required anymore from the test-suite installation targets
since the proper dependency is now encoded between cxx and
cxx_experimental.

NOKEYCHECK=True
GitOrigin-RevId: 4ffd373e3853ebc00fb339611e215deab682a54c
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index fadc818..bc09020 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -23,9 +23,6 @@
                                                --component "${target}")
   add_dependencies(cxxabi-test-depends libcxxabi-test-suite-install-${target})
 endforeach()
-if (TARGET cxx_experimental)
-  add_dependencies(libcxxabi-test-suite-install-cxx cxx_experimental)
-endif()
 
 pythonize_bool(LIBCXXABI_USE_LLVM_UNWINDER)