[CI/Bugfix]--fix ci to use non-buggy mypy vers, hypothesis vers compat w/python 3.6

[jturner65]

Motivation and Context

This PR restricts CI to use expected versions of mypy and hypothesis, since both have recently had changes which either have bugs or dropped support for python 3.6. This PR restricts mypy to v0.910 and hypothesis to 6.29.3 (conda-available version that supports python 3.6).

How Has This Been Tested

Locally all tests pass, and versions are available.

Types of changes

• Docs change / refactoring / dependency upgrade
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have completed my CLA (see CONTRIBUTING)
• I have added tests to cover my changes.
• All new and existing tests passed.