"Probe Scraper: Error on parsing metric or ping files Inbox" emails could be nicer

[chutten]

The emails we get on the mailing list are informative, but I think they could be better.

I think it'd be really helpful if the emails contained:

• Front matter to introduce what this email is and what it means. Does this mean schema deploys are blocked until they're fixed? Does this mean everything is gonna be broken until a button is pushed?
• Repository names so that the SHAs make sense
• Back matter to explain what should be done about this. Should it be ignored unless it happens again? Should we engage on #glean-dev to find a solution?