[BUG] 1965 Split up embedding functions - Redux

[atroyn]

Description of changes

The original attempt to split up the embedding functions failed because of python 3.9 and 3.10 incompatibilities with issubtype.

Original PR here: https://github.com/chroma-core/chroma/pull/2034

Failing tests here: https://github.com/chroma-core/chroma/actions/runs/9605053108/job/26491923410

The fix is changing issubtype to isinstance, which has the same functionality.

Test plan

Along with CI, tested locally with python 3.9 and 3.10 and confirmed passing.

Documentation Changes

N/A

[github-actions[bot]]

Reviewer Checklist

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Testing, Bugs, Errors, Logs, Documentation

• [ ] Can you think of any use case in which the code does not behave as intended? Have they been tested?
• [ ] Can you think of any inputs or external events that could break the code? Is user input validated and safe? Have they been tested?
• [ ] If appropriate, are there adequate property based tests?
• [ ] If appropriate, are there adequate unit tests?
• [ ] Should any logging, debugging, tracing information be added or removed?
• [ ] Are error messages user-friendly?
• [ ] Have all documentation changes needed been made?
• [ ] Have all non-obvious changes been commented?

  System Compatibility

• [ ] Are there any potential impacts on other parts of the system or backward compatibility?
• [ ] Does this change intersect with any items on our roadmap, and if so, is there a plan for fitting them together?

  Quality

• [ ] Is this code of a unexpectedly high quality (Readability, Modularity, Intuitiveness)