Pubtools-quay

* Fix race condition in parallel container pushes
* Delete signatures in parallel
* Do not execute iib operation on fbc errors
* Better error message when operator item fails due to fbc inconsistency
* Change FBC logic to not call IIB only when ocp_version >=4.13
* Unpin requests-mock version
* Set request threads for uploading signatures
* Reformatted with new tox version
* Added support for FBC operators
* Drop Python2 support
* Use namespace from index image target settings
* Make iib_deprecation_list_url optional target settings

- Verify bundles presence
- Remove arches in IIB request

* Use real task ID for tag docker signing
* Get intermediate repo from build details

* Remove duplicate destinations when pushing docker
* Listen on specific sub topic on signing service

* Fix arch of amd64 image
* Return empty manifest claims when there's nothing to sign
* Remove sorting of Push items
* Unpin the version of python-qpid-proton
* Remove created from claim message
* Change condition to not require hashing
* Push multiarch image when the current destination doesn't have a ML
* Poll for consistent results of whether a tag exists