imbrium 3.0.0

• chore!: changed from temp library keras_core to keras > 3.0.0
• chore!: removed python 3.8 support to accommodate tensorflow and keras dependencies
• chore: increased major to 3.0.0 to align with keras major
• feat: added evaluate_model method to test model performance on test data
• refactor!: removed validation split from fit_model. Control validation and test split via evaluation_split and validation_split parameters in class variables

What's Changed

• imbrium 3.0.0 by @maxmekiska in #10

Full Changelog: v2.1.0...v3.0.0