core: Allow usage of gpgtar also for new enough gpg 2.2
* src/engine-gpg.c (have_usable_gpgtar): New. (start): Always pass --status-fd to the called process. (gpg_decrypt, gpg_encrypt, gpg_encrypt_sign, gpg_sign, gpg_verify): Use have_usable_gpgtar() to check for suitable gpg.
The version check in start() is not needed because versions of gpg
that are unsuitable for the usage of gpgtar are rejected already by
the callers.
- GnuPG-bug-id: T6342