What is this in my Windows 10 PC recycle bin: iPad_10.2_2020_16.1.1_20B101_Restore.ipsw

Your PC’s Recycle Bin can be safely erased.

The illustrated Restore.ipsw file specifically relates to iPadOS 16.1.1 - this files perhaps having been previously used to restore your iPad. This file is no longer digitally signed - and cannot be used again.

iPadOS 16.4.1 is current. If you haven’t already updated to this version of iPadOS, you should do so as soon as practicable. iPadOS 16.4.1 includes essential system security updates.

Perhaps an old iPad data restore file.

If you make regular backups and regular data restores of ypur iPad, some files might be replaced with a newer file and the older, but duplicate named file is sent to the trash.