Change default to transmission_compile_latest: False

[holta]

While Transmission's compile almost always completes (within an hour, or much less on a modern CPU) the downside is that Transmission 4.0.5+ 's systemd service often fails to start after that (in recent weeks especially).

So let's revert IIAB's default to OS's age-old Transmission 3.0 from 2020-05-22 for now.

A fringe benefit of reverting above-and-beyond [1] much more reliable and [2] much faster Transmission installs (e.g. as part of MEDIUM-sized and LARGE-sized IIAB) is that the [3] age-old Transmission 3.0 executables (from apt, i.e. from the OS) are also far more compact.

Background:

• MongoDB 4.4, 5.0 & 6.0RC1 don't run on Ubuntu 22.04 (preventing Sugarizer install) [missing apt package libssl1.1 -> libssl3 ?] #3190
• PR WIP: Try 'transmission_compile_latest: True' BitTorrent software (e.g. Transmission 4.1.0-dev, instead of 3.0 from May 2020) #3599