GRegex as PCRE wrapper was introduced in GLib-2.14. PCRE was required
for MC on OSes with GLib < 2.14. Currently MC requires GLib >= 2.32.
Since 2.73.2 (released at 2022-07-08), GRegex is based on PCRE2.
We can remove PCRE and PCRE2 from MC and use GLib only.
Signed-off-by: Andrew Borodin <aborodin@vmail.ru>