Fix: deep diff ignores double underscore entries. Switched to _BULK_HASH

[AKrantzPS]

This pull request introduces several improvements and fixes across configuration, code style, and testing. The main focus is on enhancing the handling of bulk hash attributes in the codebase, ensuring correct diff detection, and improving type annotations for clarity. Additionally, there are minor updates to Dependabot configuration for commit message consistency.

Bulk Hash Attribute Handling and Diff Improvements

• Replaced all uses of __BULK_HASH and __BULK_HASH_CALCULATION_ERROR with _BULK_HASH and _BULK_HASH_CALCULATION_ERROR in collect.py to ensure these fields are not treated as private and ignored by diff tools like DeepDiff.
• Added tests verifying that differences in _BULK_HASH are detected by the diff logic, and that double underscore-prefixed fields (e.g., __BULK_HASH) are ignored, explaining the rationale for the naming change.

Type Annotation and Code Style Improvements

• Added explicit type annotations for lists and variables in collect.py to improve code clarity and maintainability. [1] [2]
• Updated assignment of pandas DataFrame columns to use pd.Index for explicitness and consistency. [1] [2]

CI and Dependency Management

• Updated .github/dependabot.yml to add commit message prefixes for dependency updates, standardizing messages for both general and CI-related dependency changes. [1] [2]