fix(tests): mkdir not mrkdir

[RossMurr4y]

Description

Fix typo.

Motivation and Context

There was a typo. I fixed it.

How Has This Been Tested?

Tested mrkdir wasn't a thing. It wasn't a thing.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• Refactor (non-breaking change which improves the structure or operation of the implementation)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Followup Actions

• None

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.
• None of the above.