Disable shared library building for thirdparty libraries

Specifically, the fmt CMake has defaulted to not specifying the library
type to build, so without BUILD_SHARED_LIBS=OFF set, it might try to
build it as a shared library, which we don't want.

thirdparty/CMakeLists.txt

@@ -21,6 +21,9 @@
 #  51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 #
 
+# Disable shared library building for all thirdparty libraries
+set( BUILD_SHARED_LIBS OFF )
+
 # Note: The glew folder isn't added here because it is added inside the main CMakeLists.txt
 
 set( ARGPARSE_INSTALL OFF )