Consider removing unnecessary AllowEmptyTelemetry task usage from Crossgen Targets

[baronfel]

In #82805 (and related) we had to update the AllowEmptyTelemetry task usage in the Crossgen targets to account for changes in the upstream SDK targets, which are the ones that customers actually use. While maintaining parity for the copies in this repo is important, in order to reduce the blast radius of other SDK changes we should consider removing the use of AET entirely here, in the 7.0 and 8.0 code flows.

It should be enough to remove this range from the 7.0 and main branches.

I couldn't figure out the best area label to add to this issue. If you have write-permissions please help me learn by adding exactly one area label.

[davidwrighton]

Seems like a good idea to me.