slack-desktop: update to 2.8.0.

Closes: #7817 [via git-merge-pr]

srcpkgs/slack-desktop/template

@@ -1,6 +1,6 @@
 # Template file for 'slack-desktop'
 pkgname=slack-desktop
-version=2.7.1
+version=2.8.0
 revision=1
 only_for_archs="x86_64"
 short_desc="A messaging app for teams"
@@ -10,7 +10,7 @@ homepage="https://slack.com/"
 repository="nonfree"
 restricted=yes
 nopie=yes
-checksum=daf046ce1c40e2d514b449055334785d51ccf45009931d7e8ad15190e93041d9
+checksum=15626e80dfef62d9f26d1c46987f4a6b333d722d49513797913e238741c4700a
 distfiles="https://slack-ssb-updates.global.ssl.fastly.net/linux_releases/slack-desktop-${version}-amd64.deb"
 
 do_extract() {