Fix build with meson >=1.9.1

Index: external/basis_universal/meson.build
--- external/basis_universal/meson.build.orig
+++ external/basis_universal/meson.build
@@ -18,8 +18,8 @@ cpp_options = [
 enable_ktx2 = get_option('enable_ktx2')
 enable_ktx2_zstd = enable_ktx2 and get_option('enable_ktx2_zstd')
 
-cc = meson.get_compiler('cpp')
-cc_native = meson.get_compiler('cpp', native : true)
+cc = meson.get_compiler('c')
+cc_native = meson.get_compiler('c', native : true)
 
 dep_m = cc.find_library('m', required : false)
 dep_m_native = cc_native.find_library('m', required : false)
