[GIP-68] Remove FRAX LM rewards

FIP-119 by Frax DAO, thanks to Samuel's help and the chad Frax contributors (https://gov.frax.finance/t/fip-119-create-gearbox-amo/1887) - established a Frax -> Gearbox AMO with a starting limit of 2M. To help bootstrap this as strategy from the Gearbox side, LM rewards were added to this passive lending pool, with GIP-30: https://gov.gearbox.fi/t/gip-30-lm-adjustment-1/1875. The rewards for FRAX are 0.168% GEAR of total supply yearly, or ~80K USD yearly currently. Not huge at current levels, but just pointing out.

Due to high borrow min limits for Credit Accounts, minimum sizes of CAs star…