The pcre2 API was changed from
pcre2_substring_list_free(PCRE2_SPTR *)
to
pcre2_substring_list_free(PCRE2_UCHAR **)
in 10.43. The difference is a `const` qualifier. Work around this.
Closes#1869
Change-Id: Ib3dd3003352f6c3155bb47d69ecb7a1b02f4647a
(cherry picked from commit 4ebebe08d8)