Made AYON connection env var optional

[kalisp]

Changelog Description

Previous implementation used AYON to control env necessary to connect to AYON server to generate environments for injection. This should be not necessary, as these env vars should be set on worker nodes only (and at least AYON_EXECUTABLE could be different), most likely with some studio automatization.

Additional review information

Old implementation depended on AYON_EXECUTABLE, AYON_SERVER_URL and AYON_API_KEY to be set on AYON side, most likely in Applications.

Testing notes:

1. set required env vars on worker nodes
2. publish without setting same environment vars in AYON, shouldnt fail

[MustafaJafar]

Can AYON_API_KEY be added to those file in rr_root?

[kalisp]

AYON_API_KEY

Not sure I follow. You mean configuration file (in similar fashion as in Deadline)? Most likely (but even DL has option to override those with env vars set on specific workers).