Pin pyOpenSSL to <= 21.0.0

[khushboobhatia01]

pyOpenSSL 22.0.0 requires cryptography>=35.0 causing dependancy conflicts https://app.circleci.com/pipelines/github/StackStorm/st2/2631/workflows/9226c6bb-50c4-46fc-a71e-f707d7ce01bf/jobs/14228

[arm4b]

More context for the history:

[package: st2] [12:05:10]      The conflict is caused by:
[package: st2] [12:05:10]          The user requested cryptography==3.4.7
[package: st2] [12:05:10]          paramiko 2.7.2 depends on cryptography>=2.5
[package: st2] [12:05:10]          requests[security] 2.25.1 depends on cryptography>=1.3.4; extra == "security"
[package: st2] [12:05:10]          pyopenssl 22.0.0 depends on cryptography>=35.0

[arm4b]

Thanks for fixing the build 👍