Purpose of the change

Fix race conditions for test setup.
https://github.com/MemMachine/MemMachine/actions/runs/21809416843/job/62918512906
https://github.com/MemMachine/MemMachine/actions/runs/21770765203/job/62817615278

Description

Some tests require NLTK download.
NLTK download uses the following loop, which allows processes to see "bad" zip files before they are fully downloaded.

            infile = urlopen(info.url)
            with open(filepath, "wb") as outfile:
                num_blocks = max(1, info.size / (1024 * 16))
                for block in itertools.count():
                    s = infile.read(1024 * 16)  # 16k blocks.
                    outfile.write(s)
                    if not s:
                        break
                    if block % 2 == 0:  # how often?
                        yield ProgressMessage(min(80, 5 + 75 * (block / num_blocks)))
            infile.close()

Type of change

• 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 not work as expected)
• Refactor (does not change functionality, e.g., code style improvements, linting)
• Documentation update
• Project Maintenance (updates to build scripts, CI, etc., that do not affect the main project)
• Security (improves security without changing functionality)

How Has This Been Tested?

Existing tests should pass more often.

• Unit Test
• Integration Test
• End-to-end Test
• Test Script (please provide)
• Manual verification (list step-by-step instructions)

Checklist

• I have signed the commit(s) within this pull request
• My code follows the style guidelines of this project (See STYLE_GUIDE.md)
• I have performed a self-review of my own code
• I have commented my code
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added unit tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• I have checked my code and corrected any misspellings

Maintainer Checklist

• Confirmed all checks passed
• Contributor has signed the commit(s)
• Reviewed the code
• Run, Tested, and Verified the change(s) work as expected