configure.ac: bump minimum required versions for glib and cairo. glib2 >= 2.30 is needed for g_unicode_script_from_iso15924() and g_unicode_script_to_iso15924() cairo >= 1.10 is needed for the new cairo_operator_t members like CAIRO_OPERATOR_SCREEN Reference issue: https://github.com/harfbuzz/harfbuzz/issues/4577 Reference issue: https://github.com/harfbuzz/harfbuzz/issues/4624