[clang][test] Fix -DBUILD_SHARED_LIBS build by adding depency on Targ… (#130105)

…etParser from clangTesting

Commit 979c275 (#129868) introduced a
dependency on the llvm::Triple::Triple in `lookupTarget`. This is part
of TargetParser, which wasn't listed in
clang/lib/Testing/CMakeLists.txt. This broke the
-DBUILD_SHARED_LIBS=True builds.

Fixes #130112

Author: kito-cheng