Remove out-of-date beta firmwares

[rmackay9]

Bug Report

During the release of 4.7.0-beta8 I noticed that these out-of-date firmwares were on the build server

(crossing out here as addressed -pb)

skyviper-v2450 (Copter)
bebop (Sub, Tracker)
disco (Sub, Tracker)
revo-mini-sd (Sub)
JHEMCU-GSF405A (Sub)
FlywooF405S-AIO (Sub)
JHEMCU-GSF405A-RX2 (Sub)

I think we should delete these shouldn't we?

[peterbarker]

I think we should delete these shouldn't we?

No, at least one is legitimately broken in this beta.

../../libraries/AP_Compass/AP_Compass.cpp: In member function 'void Compass::_probe_external_i2c_compasses()':
../../libraries/AP_Compass/AP_Compass.cpp:1264:42: error: 'AP_COMPASS_IST8310_DEFAULT_ROTATION' was not declared in this scope
 1264 |         enum Rotation default_rotation = AP_COMPASS_IST8310_DEFAULT_ROTATION;
      |                                          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

[peterbarker]

Closing this one - I removed the out-of-date ones and the other (skyviper) is being fixed by @rmackay9 with a cherry-pick.