Update to glib 2.62.6 and iOS / Android fixes
glib.recipe: Bump to 2.62.6
glib.recipe: iOS build fixes Sync the host_system == ios change with upstream, and don't look for `_NSGetEnviron()` on iOS. This regressed when moving to Meson since it was set via `ac_cv_func__NSGetEnviron` in `ios.config` and was missed.
config: Remove glib-specific autoconf hacks These haven't been used ever since glib was ported to Meson: glib_cv_stack_grows is now set as a cross property glib_cv_uscore is correctly detected with meson getpwuid_r is correctly detected with meson getgrgid_r is correctly detected with meson wchar_t is available and things work fine (added in 2013, no notes) _NSGetEnviron is fixed in the previous commit