Fix thread library linkage type.

src/libclothBW/CMakeLists.txt

src/libcorotationalLinearFEM/CMakeLists.txt

src/libglslPhong/CMakeLists.txt

src/libisotropicHyperelasticFEM/CMakeLists.txt

src/libmassSpringSystem/CMakeLists.txt

src/libstvk/CMakeLists.txt