[BEAM-13590] Renaming collections.Iterable to collections.abc.Iterable.

[blais]

In Python 3.10, the symbols under collections.abc.* are removed from collections.*.
They have been deprecated since 3.3.

(There may be other collections.abc to be replaced as well but this allows me to run some of the examples.)

[codecov]

Codecov Report

Merging #16414 (d10296c) into master (7487bf0) will increase coverage by 8.99%.
The diff coverage is 80.00%.

@@            Coverage Diff             @@
##           master   #16414      +/-   ##
==========================================
+ Coverage   74.64%   83.63%   +8.99%     
==========================================
  Files         647      450     -197     
  Lines       81385    61862   -19523     
==========================================
- Hits        60747    51740    -9007     
+ Misses      19667    10122    -9545     
+ Partials      971        0     -971     

Impacted Files	Coverage Δ
.../apache_beam/runners/direct/transform_evaluator.py	90.31% <ø> (ø)
sdks/python/apache_beam/transforms/trigger.py	89.86% <0.00%> (ø)
...ks/python/apache_beam/runners/worker/sideinputs.py	87.96% <100.00%> (ø)
sdks/python/apache_beam/typehints/typecheck.py	97.54% <100.00%> (ø)
sdks/python/apache_beam/typehints/typehints.py	93.43% <100.00%> (ø)
sdks/python/apache_beam/io/source_test_utils.py	88.47% <0.00%> (-1.39%)	⬇️
sdks/go/pkg/beam/transforms/stats/max.go
sdks/go/pkg/beam/forward.go
sdks/go/pkg/beam/testing/passert/floats.go
sdks/go/pkg/beam/core/graph/bind.go
... and 195 more

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[tvalentyn]

Thanks for your contribution! Looks like there were two other PRs on this: #15850 and #15415 that for some reason did not land.

#15850 looks most complete to me. I just resolved a conflict there and suggest we proceed with that PR and close this PR. Please comment on #15850 if you see any concerns as you looked at this most recently.

[tvalentyn]

Closing in favor of #15850