`git_reference_cmp` only considers the target of a reference, and
ignores the name. Meaning that a reference `foo` and reference `bar`
pointing to the same commit will compare equal.

Correct this, comparing the name _and_ target of a reference.

cmake: drop posix dependency from pcre* detection

since f585b12 neither PCRE nor PCRE2 backends rely on POSIX regex, so
reflect it in library detection logic

fix interactive rebase detect.

Fix internal git_sysdir_find* function usage within public git_config_find* functions

ntlmclient: LibreSSL 3.5 removed HMAC_CTX_cleanup

ci: update dockerfiles for mbedTLS new url

Update the new URL for mbedTLS.