net-mail/notmuch: Fix runtime dependencies
* Updated ebuild for EAPI 7.
* Fix: Earlier ebuild versions had unconditional dependencies on Sphinx
and Texinfo even at runtime. Moved dependencies to BDEPEND and tied
them to USE=doc.
* Fix: Install Texinfo documentation only when USE=doc is specified.
Closes: https://bugs.gentoo.org/711052
Package-Manager: Portage-2.3.99, Repoman-2.3.22
Signed-off-by: Ralph Seichter <gentoo@seichter.de>
Closes: https://github.com/gentoo/gentoo/pull/15918
Signed-off-by: Andreas K. Hüttel <dilfridge@gentoo.org>