- build against modern python on sle15

- drop patches:
* Reduce memory consumption of MessageSet parsing
* Add back a filegroup for :well_known_protos (#10061)
* Fix shadowing warnings
* Fix for issue #8484, constant initialization doesn't compile in msvc clang-cl environment
* Use ArrayList copy constructor
* Fix ReferenceError: window is not defined when getting the global object
* Fix memory leak in MessageClass.encode
* Override Map.clone to use Map's dup method
* Ruby: build extensions for arm64-darwin
* Add class method Timestamp.from_time to ruby well known types
* Adopt pure ruby DSL implementation for JRuby
* Fix for descriptor_pb.rb: google/protobuf should be required first
* Add python-requires in setup.py
* Add python 3.10