[FIP - 438] Discontinue OFT Token Support on Deprecated and Inactive Chains

## Authors Frax Core Team # Summary This proposal discontinues Native OFT Token issuance for specific chains that are either officially deprecated by their core teams or have exhibited prolonged inactivity and minimal user adoption. The affected deployments include Frax OFT assets such as frxUSD, sfrxUSD, frxETH, sfrxETH, FPI, and WFRAX. Discontinuing support will simplify network operations, reduce risk exposure, and ensure efficient maintenance of the active Frax Mesh. # Background and...