Just encountered this problem myself – luckily I was able to find the password in some Gradle’s temporary file. Just in case anyone lands here:
try looking for this file
and search for
It was there in cleartext. In general, if you do remember at least a part of your password, try searching for a file containing this substring and hopefully you will fish out something.
Wanted to throw it out here, maybe it will eventually help someone.
Edit: Added new insight from comments, just to be more visible.
Edit 2: Added some more locations reported in comments.
Thanks to Vivek Bansal, Amar Ilindra and Uzbekjon for these.