text: Title: [BUG] mypi typecheck error
  Body: **Describe the bug**
  
  ci on py3.9 on main:
  
  ```
  + mypy --version
  mypy 0.[9](https://github.com/graphistry/pygraphistry/actions/runs/3185568420/jobs/5195293562#step:7:10)82 (compiled: yes)
  + mypy --config-file mypy.ini graphistry
  graphistry/util.py:62: error: Argument 1 to "sha256" has incompatible type "Union[ExtensionArray, ndarray[Any, Any]]"; expected "Union[bytes, Union[bytearray, memoryview, array[Any], mmap, _CData]]"
  Found 1 error in 1 file (checked 58 source files)
  Error: Process completed with exit code 1.
  ```
  
  **To Reproduce**
  
  Likely via local docker tests as well (`docker $ ./test-cpu-local-minimal.sh`)`), maybe setting the python version to 3.9
  
  **Expected behavior**
  Typechecks
  
  **Actual behavior**
  Didn't
  
  **Screenshots**
  
  **Browser environment (please complete the following information):**
  
  **Graphistry GPU server environment**
  
  **PyGraphistry API client environment**
  
  `test-core-python` / `3.9` in 
  
  https://github.com/graphistry/pygraphistry/actions/runs/3185568420/jobs/5195293562
  
  **Additional context**
  
  Unclear if fp (suppression) or something around pandas upstream needing a real fix