chore: Drop Python 3.9 support (#322) #157

Job	Run time
Build, Tag, and Push Image (examples/map/forward_message)	3m 49s
Build, Tag, and Push Image (examples/map/multiproc_map)	3m 45s
Build, Tag, and Push Image (examples/map/even_odd)	4m 2s
Build, Tag, and Push Image (examples/map/flatmap)	3m 43s
Build, Tag, and Push Image (examples/reducestream/counter)	3m 51s
Build, Tag, and Push Image (examples/reduce/counter)	4m 0s
Build, Tag, and Push Image (examples/sideinput/simple_sideinput/udf)	4m 9s
Build, Tag, and Push Image (examples/sideinput/simple_sideinput)	3m 58s
Build, Tag, and Push Image (examples/mapstream/flatmap_stream)	3m 49s
Build, Tag, and Push Image (examples/sink/log)	3m 34s
Build, Tag, and Push Image (examples/source/simple_source)	3m 49s
Build, Tag, and Push Image (examples/reducestream/sum)	3m 46s
Build, Tag, and Push Image (examples/sink/async_log)	3m 47s
Build, Tag, and Push Image (examples/sourcetransform/event_time_filter)	3m 48s
Build, Tag, and Push Image (examples/batchmap/flatmap)	3m 54s
Build, Tag, and Push Image (examples/accumulator/streamsorter)	3m 58s
	1h 1m 42s

Provide feedback