v0.12.4

🚀 Enhancements

• Set BQ staging max time travel to minimum 2 days by @shnapz in #4697

🐛 Bug Fixes

• Fix SingletonCoder serialization by @RustedBones in #4691
• Unwrap internal SCollection coders to be reused in transforms by @RustedBones in #4690
• Make Parquet-SplittableDoFn opt-in, not opt-out by @clairemcginty in #4700

📗 Documentation

• Update 0.12 migration with lookup do fn by @RustedBones in #4695
• Document ScioIO methods, fixes #3937 by @kellen in #4689
• Update SBF docs, fixes #4528 by @kellen in #4693

🌱 Dependency Updates

• Update scalafmt-core to 3.7.1 by @scala-steward in #4682
• Update sbt-jmh to 0.4.4 by @scala-steward in #4688
• Use slf4j version from beam by @RustedBones in #4696

Full Changelog: v0.12.3...v0.12.4