Fix TensorFlow dependency

[nwittler]

What

Lock tf version to 2.14.1

Why

tf version 2.15 changed an interface to check for tensor types, resulting in AttributeError: module 'tensorflow.python.framework.ops' has no attribute 'Tensor'

How

Update setup.py

Remarks

While unmaintained right now, this keeps dev functional.

Checklist

Please include and complete the following checklist. Your Pull Request is (in most cases) not ready for review until the following have been completed. You can create a draft PR while you are still completing the checklist. Check the Contribution Guidelines for more details. You can mark an item as complete with the - [x] prefix

• [ ] Tests - Added unit tests for new code, regression tests for bugs and updated the integration tests if required
• [ ] Formatting & Linting - black and flake8 have been used to ensure styling guidelines are met
• [ ] Type Annotations - All new code has been type annotated in the function signatures using type hints
• [ ] Docstrings - Docstrings have been provided for functions in the numpydoc style
• [ ] Documentation - The tutorial style documentation has been updated to explain changes & new features
• [ ] Notebooks - Example notebooks have been updated to incorporate changes and new features
• [ ] Changelog - A short note on this PR has been added to the Upcoming Release section

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (48b7917) 76.67% compared to head (112c875) 76.67%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## dev #241 +/- ## ======================================= Coverage 76.67% 76.67% ======================================= Files 38 38 Lines 5873 5873 ======================================= Hits 4503 4503 Misses 1370 1370 ```

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