- The `SUPERFLUOUS_NO_LINT` warning has been removed from the glinter.
It likely did more harm than good, and makes it hard to make
`metrics.yaml` files that pass across different versions of
`glean_parser`.
- Expired metrics will now produce a linter warning, `EXPIRED_METRIC`.
- Expiry dates that are more than 730 days (\~2 years) in the future
will produce a linter warning, `EXPIRATION_DATE_TOO_FAR`.
- Allow using the Quantity metric type outside of Gecko.
- New parser configs `custom_is_expired` and `custom_validate_expires`
added. These are both functions that take the `expires` value of the
metric and return a bool. (See `Metric.is_expired` and
`Metric.validate_expires`). These will allow FOG to provide custom
validation for its version-based `expires` values.