Use proper Slack variable for `@here` mentions
More info on this special Slack message variable can be found here:
@@ -4,7 +4,7 @@ current=$(curl https://packages.chef.io/manifests/current/automate/latest.json 2
acceptance=$(curl https://packages.chef.io/manifests/acceptance/automate/latest.json 2>/dev/null | jq -r '.git_sha');
read -r -d '' message <<EOF
-@here :success: A2 has been promoted from \`dev\` to \`acceptance\` :success:
+<!here> :success: A2 has been promoted from \`dev\` to \`acceptance\` :success:
The list of changes can be found here: https://github.com/chef/automate/compare/${current}...${acceptance}
