Enable electron LRT chains

This enables electron LRT chains. A different set were disabled because of irreducible counts (ATR-23564). As discussed there, this hasn't been reproduced offline and some other updates that might correct this issue have gone in. These chains are candidates for the physics menu, and a higher stats test of the rate from a reprocessing would be useful.

The CI should be tested a few times to check if there are still any count changes before merging.

Edit: It has passed 5 times now without count changes. I hope that is a sufficient check that this is unlikely to cause irreducible counts.