This reverts commit 275ecb2623.
This had to be reverted because it breaks exception handling which is a critical problem.
With the updated code any exception thrown inside code that had a JITed call stack would crash.
This makes sure the internal versions of these libraries bundled with
the GZDoom source code is used. This prevents the system from building
GZDoom for dynamic linking with incompatible external libraries (see
<https://forum.zdoom.org/viewtopic.php?f=2&t=64633>).
# Conflicts:
# glslang/glslang/CMakeLists.txt
# glslang/spirv/CMakeLists.txt
