Turn build error into config error

I can configure without a required package but fail to build

```
[0/2] Re-checking globbed directories...
[1/353] Building CXX object src/CMakeFiles/ppx.dir/ppx/window_glfw.cpp.o
FAILED: [code=1] src/CMakeFiles/ppx.dir/ppx/window_glfw.cpp.o
/usr/bin/c++ -DGLFW_INCLUDE_NONE -DPPX_LINUX -DPPX_LINUX_XCB -DPPX_VULKAN -DRELATIVE_PATH_TO_PROJECT_ROOT=\"..\" -DSTACK_LINE_READER_BUFFER_SIZE=1024 -I/usr/local/google/home/hitchens/git/bigwheels/src -I/usr/local/google/home/hitchens/git/bigwheels/include -I/usr/local/google/home/hitchens/git/bigwheels/third_party/glfw/include -I/usr/local/google/home/hitchens/git/bigwheels/third_party/glm -I/usr/local/google/home/hitchens/git/bigwheels/third_party/gli -I/usr/local/google/home/hitchens/git/bigwheels/third_party/stb -I/usr/local/google/home/hitchens/git/bigwheels/third_party/imgui -I/usr/local/google/home/hitchens/git/bigwheels/third_party/tinyobjloader -I/usr/local/google/home/hitchens/git/bigwheels/third_party/pcg32 -I/usr/local/google/home/hitchens/git/bigwheels/third_party/cgltf -I/usr/local/google/home/hitchens/git/bigwheels/third_party/xxHash -I/usr/local/google/home/hitchens/git/bigwheels/third_party/utfcpp/source -I/usr/local/google/home/hitchens/git/bigwheels/third_party/json/single_include -I/usr/local/google/home/hitchens/git/bigwheels/third_party/VulkanMemoryAllocator/include -I/usr/local/google/home/hitchens/git/bigwheels/third_party/VulkanMemoryAllocator/src -I/usr/local/google/home/hitchens/vulkan_sdk/1.4.335.0/x86_64/include -I/usr/local/google/home/hitchens/git/bigwheels/third_party/cpu_features/include -Werror -std=c++17 -fdiagnostics-color=always -Wno-nullability-completeness -Wno-deprecated-anon-enum-enum-conversion -Wno-missing-field-initializers -Wno-unused-parameter -Wno-ignored-qualifiers -Wno-deprecated-copy -Wno-deprecated-enum-enum-conversion -Wno-pointer-bool-conversion -O3 -DNDEBUG -std=gnu++17 -MD -MT src/CMakeFiles/ppx.dir/ppx/window_glfw.cpp.o -MF src/CMakeFiles/ppx.dir/ppx/window_glfw.cpp.o.d -o src/CMakeFiles/ppx.dir/ppx/window_glfw.cpp.o -c /usr/local/google/home/hitchens/git/bigwheels/src/ppx/window_glfw.cpp
/usr/local/google/home/hitchens/git/bigwheels/src/ppx/window_glfw.cpp:26:10: fatal error: X11/Xlib-xcb.h: No such file or directory
26 | #include
| ^~~~~~~~~~~~~~~~
compilation terminated.
```

In this case, I needed to install libx11-xcb-dev.

It would be nice if CMake caught this for me earlier