According to this you can:
www.theiphonewiki.com
What that means is you can update the iPad Air 2 to iPadOS 14.5.1 and then re-jailbreak with checkra1n. Then you have to reinstall Cydia with the iOS checkra1n app and then re-install all the tweaks and other jailbreak stuff you want.
What I don't know is how well the jailbreak works or if the tweaks you currently have installed will work. I advise you to research thoroughly.