fail config with SKIP_SPIRV_TOOLS_INSTALL=ON

when try build/install with `SKIP_SPIRV_TOOLS_INSTALL=ON`, gets

~~~
CMake Error: install(EXPORT "SPIRVTargets" ...) includes target "SPIRV" which requires target "SPIRV-Tools-opt" that is not in any export set.
~~~

all cmake flags i use:
~~~
cmake .. \
-DCMAKE_BUILD_TYPE=None \
-DCMAKE_INSTALL_PREFIX=/usr \
-DCMAKE_INSTALL_LIBDIR=lib32 \
-DBUILD_TESTING=OFF \
-DBUILD_SHARED_LIBS=ON \
-DCMAKE_SKIP_RPATH=ON \
-DSPIRV_SKIP_EXECUTABLES=ON \
-DENABLE_GLSLANG_BINARIES=OFF \
-DENABLE_SPIRV_TOOLS_INSTALL=OFF \
-DENABLE_SPVREMAPPER=OFF \
-DSKIP_SPIRV_TOOLS_INSTALL=ON
~~~