Update 3.4 branch after commits in master#593

Merged

asenyaev merged 4 commits intoopencv:3.4from

asenyaev:asen/new_update_3.4_branch

Dec 16, 2021

Commits on Dec 7, 2021

Use PEP-508 compliant dependency specifiers

amyreese
authored and
asenyaev
committed
Delete appveyor.yml

cclauss
authored and
asenyaev
committed

Commits on Dec 15, 2021

Added python limited API support
asenyaev
committed

Commits on Dec 16, 2021

Changed a path to config-X.py file after python limited API support, optimized uploading and downloading artifacts
asenyaev
committed