When sending irc notifications, insert a zero-width space after the
first character of the username of the author of issues, to prevent that
user from receiving a ping.
Fixes: b/95
Change-Id: Ibcacb45129b2cb99b587744eb61f4f1dbc0060d6
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2693
Tested-by: BuildkiteCI
Reviewed-by: tazjin <mail@tazj.in>