sendmail: update to 8.18.1
- Fix GCC 15 build with 2 patches from Gentoo [1][2]
- Refresh existing patch
- Extend 010-enable-nonroot-install.patch to remove "-o U -g G" from
more install targets (fixes 'invalid user buildbot' in CI)
[1]: https://github.com/gentoo/gentoo/blob/master/mail-mta/sendmail/files/sendmail-8.18.1-c23-sm_strtoll.patch
[2]: https://github.com/gentoo/gentoo/blob/master/mail-mta/sendmail/files/sendmail-8.18.1-c23-ctime.patch
Co-authored-by: W. Michael Petullo <[email protected]>
Signed-off-by: Aleksey Vasilenko <[email protected]>