libweston/color-management: Add fallback for static_assert
Attempt to fix the following with clang-18:
../weston-9999/libweston/color-management.c:890:2: error: call to undeclared function 'static_assert'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration] 890 | static_assert(UINT32_MAX <= SIZE_MAX, | ^
Fixes: #948 (closed)
Signed-off-by: Marius Vlad marius.vlad@collabora.com