Experiment: fast compiling fontique

[nicoburns]

An experiment in making Fontique compile fast. Brings clean build time down to around 4 seconds.

Depends on:

• Remove kurbo and peniko dependencies #414
• Upgrade to icu4x 2.0 #418
• [read-fonts] Add per-table feature flags googlefonts/fontations#1658 (<--- biggest win)

Futher possible improvements:

• Remove icu_locale_core dep
• Convince read-fonts to add an option to use unsafe bytemuck impls rather than bytemuck_derive
• Potentially making the CharmapIndex optional

(failing CI because HarfRust version of read-fonts doesn't match version used by Parley/Fontique in this PR)

Full build timings

[nicoburns]

Doesn't look like fontations are going to accept the "feature flagged" tables PR. So might as well close this.