feat: add revision parameter to Sentence Transformers embedder components

[swapniel99]

Related Issues

None

Proposed Changes:

Added a revision parameter to all Sentence Transformers embedder components to allow users to specify a specific model revision/version from the Hugging Face Hub. This parameter is passed through to the underlying Sentence Transformers backend.

How did you test it?

• Added unit tests for all four embedder components to verify the revision parameter is correctly:
  • Initialized with default value (None)
  • Set when provided explicitly (e.g., "v1.0")
  • Serialized and deserialized in to_dict() and from_dict() methods
• Updated existing backend initialization tests to include the revision parameter
• All pre-commit hooks passed successfully

Notes for the reviewer

The revision parameter follows the same pattern as other optional parameters like trust_remote_code and local_files_only. It's passed directly to the Sentence Transformers model initialization, allowing users to pin to specific model versions for reproducibility.

Checklist

• I have read the contributors guidelines and the code of conduct
• I have updated the related issue with new insights and changes
• I added unit tests and updated the docstrings
• I've used one of the conventional commit types for my PR title: fix:, feat:, build:, chore:, ci:, docs:, style:, refactor:, perf:, test: and added ! in case the PR includes breaking changes.
• I documented my code
• I ran pre-commit hooks and fixed any issue

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[sjrl]

To avoid this being a breaking change (since we are inserting a new positional argument in the middle of existing ones) put this as the last argument in the init

[sjrl]

Same here let's move this one to the bottom of the init since this init method consists of positional arguments

[coveralls]

Pull Request Test Coverage Report for Build 18994388892

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 6 unchanged lines in 4 files lost coverage.
• Overall coverage increased (+0.002%) to 92.246%

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Files with Coverage Reduction	New Missed Lines	%
components/embedders/sentence_transformers_sparse_document_embedder.py	1	98.41%
components/embedders/sentence_transformers_sparse_text_embedder.py	1	98.08%
components/embedders/sentence_transformers_document_embedder.py	2	97.01%
components/embedders/sentence_transformers_text_embedder.py	2	96.49%

Totals
Change from base Build 18976263337:	0.002%
Covered Lines:	13502
Relevant Lines:	14637

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💛 - Coveralls