Remove SOFC Keras Surrogates And Tests

[bpaul4]

Fixes

Closes #1431

Summary/Motivation:

Remove SOFC Keras surrogates that no longer work, as they as no longer used anywhere in the codebase.

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[codecov-commenter]

Codecov Report

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

Project coverage is 76.36%. Comparing base (ff6471c) to head (8f724fb). Report is 24 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1475 +/- ## ======================================= Coverage 76.36% 76.36% ======================================= Files 394 393 -1 Lines 65136 65085 -51 Branches 14429 14426 -3 ======================================= - Hits 49743 49705 -38 + Misses 12831 12819 -12 + Partials 2562 2561 -1 ```

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[lbianchi-lbl]

Thanks a lot @bpaul4. We're trying to get #1465 merged ASAP, and then we'll merge this in whenever possible after that.