v1.8.0 release

This release includes the followings:

New feature

• Support BIP-322 full scheme verification in Bitcoin::MessageSign#verify_message
• Add testnet4 configuration(59a2402, 98acd62)
• Support ruby 3.4(8578bb6, 9d44ec2)
• Separate secp256k1 library calls into external gem
  • Remove ffi dependency since it is included in secp256k1rb

Bug fix

• Update dns seed and fix bip34 height

Other changes

• Update json_pure version to fix error that occurred when JSON::Pure::Parser was removed from 2.8.0
• Remove recover id from arguments when recovering public key from signature

Full Changelog: v1.7.0...v1.8.0