S3 storage cache backend

I was screwing around with Minio and this happened - tt-rss/ttrss-cache-s3: File cache backend using S3 protocol - ttrss-cache-s3 - Tiny Tiny RSS

  • it’s almost entirely untested but kinda works
  • you need to add php81-simplexml package to docker container (dev one has it already, i haven’t yet bothered with docker hub images)