Revert "[runtimes] Add missing test dependencies to check-all (llvm#72955)"

This caused some runtimes builds to fail with:
error: unknown target 'runtimes-test-depends'

See comments on the PR.

> The test-depends target contained all the dependencies needed to run the
> runtimes tests, but it was never added as a dependency of check-all.
> This caused some of the tsan tests to fail, since the custom libcxx
> build the tests were looking for was never built. Besides the tsan
> failures, this fixes all the other test failures I was seeing with:
> cmake -G Ninja -B release-build -S llvm \
>         -DCMAKE_POSITION_INDEPENDENT_CODE=ON \
>         -DCMAKE_BUILD_TYPE=Release \
>         -DLLVM_ENABLE_ASSERTIONS=OFF \
>         -DLLVM_ENABLE_PROJECTS="clang;lld" \
>         -DLLVM_ENABLE_RUNTIMES="libcxx;libcxxabi;libunwind;compiler-rt"
>
> This is the same configuration the test-release.sh script uses, so I'm
> hoping this will also fix all the test failures we've been seeing when
> building the releases.
>
> Fixes llvm#58680

This reverts commit 7f215b1.

Author: zmodem

llvm/CMakeLists.txt

@@ -1255,7 +1255,6 @@ if( LLVM_INCLUDE_TESTS )
   add_custom_target(test-depends
       DEPENDS ${LLVM_ALL_LIT_DEPENDS} ${LLVM_ALL_ADDITIONAL_TEST_DEPENDS})
   set_target_properties(test-depends PROPERTIES FOLDER "Tests")
-  add_dependencies(check-all test-depends)
 endif()
 
 if (LLVM_INCLUDE_DOCS)