version_1.92

fix: build the Linux package with shaderc so Vulkan actually works

render_driver already defaults to vulkan on Linux, but the Linux CI passed
-DNO_SHADERC=on, which defines DISABLE_SHADERC. GEVulkanShaderManager then
compiles no shaders and aborts with "No vulkan shaders compiled, perhaps
shaderc is not enabled", so createVulkanDriver fails and the game silently
falls back to OpenGL. The shipped version_1.91 Linux build is affected.

Install libshaderc-dev/glslang-dev/spirv-tools and link shaderc statically so
the release tarball stays self-contained; Debian's libshaderc_combined.a is not
actually self-contained and needs glslang and SPIRV-Tools resolved explicitly.

Add a post-build guard that fails if no glslang/SPIRV-Tools symbols land in the
binary, so this cannot silently regress.