v1.21.8

What's Changed

• clang-format 18 by @graebm in #548
• Update dependencies by @waahm7 in #554
• Update MacOS to arm64 by @waahm7 in #558
• Use node-16 for Mac OS arm64 by @sfod in #566
• Update submodules by @sbSteveK in #570
• Update dependencies by @sbSteveK in #571
• Prebuild aws-lc by @sfod in #564
• Continuous Delivery nodejs version bump by @sbSteveK in #573
• Revert Dependencies by @sbSteveK in #574

Full Changelog: v1.21.3...v1.21.8