Load best weights outside of finally block, since load may throw an exception

[dantreiman]

The problem here is that if model training fails before the weights are saved, the finally block will call self.model.load(save_path) which throws a FileNotFound exception, thus the original error is never printed to the console.

Python executes the finally block before raising the original exception.

This PR moves self.model.load(save_path) outside of the finally block.

[github-actions]

Unit Test Results

       4 files   -     1         4 suites   - 1   1h 20m 49s ⏱️ - 39m 37s
2 929 tests ±    0  2 883 ✔️ ±    0  46 💤 ±  0  0 ❌ ±0 
8 445 runs   - 171  8 349 ✔️  - 148  96 💤  - 23  0 ❌ ±0 

Results for commit dcd62e6. ± Comparison against base commit 9c58d5e.