2.3.7: Minor improvement

What's Changed

• Add scheme to provision by @IsaacYangSLA in #2069
• Listen host by @IsaacYangSLA in #2072
• Support 3rd-party training system integration with FLARE by @yanchengnv in #2074
• Restore non-aio grpc driver by @yanchengnv in #2077

Full Changelog: 2.3.6...2.3.7