Remove elementary-mail

It is in Arch repos since last month.

elementary-mail/PKGBUILD

@@ -1,34 +0,0 @@
-# Maintainer: Alan Orth <aorth@mjanja.ch>
-
-pkgname=elementary-mail
-pkgver=r527.bd10b27a
-pkgrel=1
-epoch=1
-pkgdesc="Mail app designed for elementary OS"
-url="https://github.com/elementary/mail"
-arch=(x86_64)
-license=(GPL3)
-depends=(libhandy evolution-data-server granite folks)
-makedepends=(git meson vala cmake)
-replaces=('pantheon-mail')
-_commit=bd10b27a3beced8354264e4475ff8fcb8897f111
-source=("$pkgname::git+https://github.com/elementary/mail.git#commit=$_commit")
-sha256sums=('SKIP')
-
-pkgver() {
-  cd "$pkgname"
-  printf "r%s.%s" "$(git rev-list --count HEAD)" "$(git rev-parse --short HEAD)"
-}
-
-prepare() {
-  cd $pkgname
-}
-
-build() {
-  arch-meson $pkgname build
-  meson compile -C build
-}
-
-package() {
-  DESTDIR="$pkgdir" meson install -C build
-}