Build Jolt as a static library;

joltc's current CMakeLists forces itself to build as a shared library on
PC/Android.  However, it builds Jolt using the current value of
BUILD_SHARED_LIBS.

We currently have BUILD_SHARED_LIBS set to ON when adding joltc, so we
end up with 2 shared libraries, which is cumbersome.  We'd rather just
have a single library for Jolt.  So instead, let's set BUILD_SHARED_LIBS
to off when adding the project, which will build Jolt as a static
library and joltc as a shared library (linking to the static library).

That way we just end up with a single shared library that contains both
joltc and Jolt.

CMakeLists.txt

@@ -187,6 +187,7 @@ if(LOVR_ENABLE_PHYSICS)
       set(LOVR_PHYSICS_LIB ode)
     endif()
   elseif(LOVR_PHYSICS_LIBRARY STREQUAL "JOLT")
+    set(BUILD_SHARED_LIBS OFF)
     set(DEBUG_RENDERER_IN_DEBUG_AND_RELEASE OFF CACHE BOOL "")
     set(PROFILER_IN_DEBUG_AND_RELEASE OFF CACHE BOOL "")
     add_subdirectory(deps/jolt-physics-sharp jolt)