CLN .format to f-strings for several files
updated to f-strings for:
pandas/tests/scalar/interval/test_ops.py
 pandas/tests/computation/test_eval.py
 pandas/tests/dtypes/*
      pandas/tests/dtypes/cast/test_infer_dtype.py
      pandas/tests/dtypes/test_dtypes.py
      pandas/tests/dtypes/test_inference.py

held off on implementing for regex match strings pending PEP 536

- [x] contributes to fstring corrections in #29547
- [x] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`


Tests failed, updating with fix.
 thanks @JMBurley 