Remove last mysql type override from APDB

[JeremyMcCormick]

There was one remaining column with a MySQL type override in the APDB schema:

- name: lcPeriodic
  "@id": "#SSObject.lcPeriodic"
  datatype: binary
  length: 768
  description: Periodic light curve features computed on phase/distance-corrected magnitudes (H), 6x32 floats.
  mysql:datatype: BLOB(768)

I don't believe this is necessary, because APDB does not use MySQL.

[andy-slac]

Looks great! There are also mysql:engine and mysql:charset keys in few places, I think you can drop them too.

[JeremyMcCormick]

Looks great! There are also mysql:engine and mysql:charset keys in few places, I think you can drop them too.

Okay, I will drop those as well. Thanks!