Don't read hdmx in glyf scaler

[dfrg]

Here: https://github.com/googlefonts/fontations/blob/756d45082d3832d0ec8bda6a30bc9b8bd1408424/skrifa/src/outline/glyf/mod.rs#L233

The whole point of the hdmx table is to provide hinted advances without having to run the TrueType interpreter. Also, some fonts have buggy hdmx tables and are only saved by the backward compatibility flag in the hinter. See #1319