[BEAM-3713] Move dataflow:validatesContainerTests from nosetest to pytest

[udim]

DO NOT MERGE, clone of 14716 for testing

Please add a meaningful description for your change here

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ValidatesRunner compliance status (on master branch)

Lang	ULR	Dataflow	Flink	Samza	Spark	Twister2
Go	---			---		---
Java
Python	---			---		---
XLang				---		---

Examples testing status on various runners

Lang	ULR	Dataflow	Flink	Samza	Spark	Twister2
Go	---	---	---	---	---	---	---
Java	---		---	---	---	---	---
Python	---	---	---	---	---	---	---
XLang	---	---	---	---	---	---	---

Post-Commit SDK/Transform Integration Tests Status (on master branch)

Go	Java	Python

Pre-Commit Tests Status (on master branch)

---	Java	Python	Go	Website	Whitespace	Typescript
Non-portable
Portable	---			---	---	---

See .test-infra/jenkins/README for trigger phrase, status and link of all Jenkins jobs.

GitHub Actions Tests Status (on master branch)

See CI.md for more information about GitHub Actions CI.

[udim]

run seed job

[udim]

run seed job

[udim]

Run Python Dataflow ValidatesContainer

[codecov]

Codecov Report

Merging #14782 (eaf3ae4) into master (c644b06) will increase coverage by 0.34%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master   #14782      +/-   ##
==========================================
+ Coverage   83.60%   83.94%   +0.34%     
==========================================
  Files         442      440       -2     
  Lines       59246    59638     +392     
==========================================
+ Hits        49531    50063     +532     
+ Misses       9715     9575     -140     

Impacted Files	Coverage Δ
...build/srcs/sdks/python/apache_beam/io/parquetio.py
...che_beam/portability/api/beam_provision_api_pb2.py
.../runners/interactive/testing/pipeline_assertion.py
...thon/apache_beam/io/azure/blobstoragefilesystem.py
...rcs/sdks/python/apache_beam/runners/direct/util.py
...pache_beam/runners/worker/worker_id_interceptor.py
.../srcs/sdks/python/apache_beam/examples/sql_taxi.py
...38/build/srcs/sdks/python/apache_beam/io/iobase.py
...beam/runners/interactive/display/pipeline_graph.py
...ild/srcs/sdks/python/apache_beam/runners/common.py
... and 872 more

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