Other LLVM projects use the suffix -depends for the test dependencies,
however LLDB uses -deps and seems to be the only project under the
LLVM to do so.
In order to make the projects more homogeneous, switch all the
references to lldb-test-deps to lldb-test-depends.
Additionally, provide a compatibility target with the old name and
depending on the new name, in order to not break anyone workflow.