Although conda lib is is LD_LIBRARY_PATH, cmake building process
still ran into erros while linking libstdc++:
```
ld:/home/centos/repo/chipyard/.conda-env/lib/libicuuc.so.73:
undefined reference to `std::condition_variable::wait(
std::unique_lock<std::mutex>&)@GLIBCXX_3.4.30'
```
Add this link flag will resolve this
7f8d7bd389