Release v0.19.0 checklist

[jedel1043]

• cargo update
• cargo +nightly fmt -- --unstable-features --config format_code_in_doc_comments=true (format code in comments #3902)
• Ensure ABOUT.md includes all workspace crates (update versions and ABOUT files #3903)
• cargo run --bin regenerate-about (update versions and ABOUT files #3903)
• Bump version on all crates (update versions and ABOUT files #3903)
• Update README.md to use the to-be-published version (Cleanup README.md and contributor documentation #3909)
• Update CHANGELOG.md (changelog for v0.19 #3904)
• Write blogpost (release v0.19 boa-dev.github.io#162)

EDIT: Testing new process of running cargo update after releasing instead of before

[jasonwilliams]

• About file and version bump update versions and ABOUT files #3903
• Changelog update versions and ABOUT files #3903