Update to use NamedTemporaryFile rather than mktemp

[claytonparnell]

Summary

tempfile.mktemp() has been deprecated (see https://docs.python.org/3/library/tempfile.html#tempfile.mktemp) due to security vulnerability, here I have taken the recommended course of action by replacing with tempfile. NamedTemporaryFile() to resolve the vulnerability. (Our sagemaker-python-sdk package uses multiprocess and was flagged for this vulnerability, please merge and release ASAP!)
I ran py3.10 tests successfully.

Checklist

Documentation and Tests

• Added relevant tests that run with python tests/__main__.py, and pass.
• Added relevant documentation that builds in sphinx without error.
• Added new features that are documented with examples.
• Artifacts produced with the main branch work as expected under this PR.

Release Management

• Added "Fixes #NNN" in the PR body, referencing the issue (#NNN) it closes.
• Added a comment to issue #NNN, linking back to this PR.
• Added rationale for any breakage of backwards compatibility.
• Requested a review.