Fixes and Functionality:

• Caseless header comparing in HTTP adapter (#2880)
• Avoid package.json import fixing issues and warnings related to this (#4041), (#4065)
• Fixed cancelToken leakage and added AbortController support (#3305)
• Updating CI to run on release branches
• Bump follow redirects version
• Fixed default transitional config for custom Axios instance; (#4052)

Huge thanks to everyone who contributed to this release via code (authors listed below) or via reviews and triaging on GitHub:

• Jay
• Matt R. Wilson
• Xianming Zhong
• Dmitriy Mozgovoy