v4.4.8

## Warning
Do not upgrade to this release if you want to preserve your existing indexed documents but have not yet run the document index migration, which can be done from any version v3.x. [See additional documentation here](https://docs.onyx.app/admins/advanced_configs/opensearch_document_index_migration#opensearch-document-index-migration).

See the assets to download this version and install.

## What's Changed
* fix(bookstack): index documents updated on the current day (#13537) to release v4.4 by @onyx-cherry-pick[bot] in https://github.com/onyx-dot-app/onyx/pull/13543
* fix(files): extract cached calculated values from xlsx, not formula strings (#13536) to release v4.4 by @onyx-cherry-pick[bot] in https://github.com/onyx-dot-app/onyx/pull/13544
* fix(sharepoint): retry empty/non-JSON Graph responses instead of aborting indexing (#13540) to release v4.4 by @onyx-cherry-pick[bot] in https://github.com/onyx-dot-app/onyx/pull/13547
* fix(chat): stop citation processor from corrupting code fences (#13538) to release v4.4 by @onyx-cherry-pick[bot] in https://github.com/onyx-dot-app/onyx/pull/13548
* fix(llm): degrade and retry provider-rejected reasoning params (backport of #13378 to release/v4.4) by @justin-tahara in https://github.com/onyx-dot-app/onyx/pull/13619
* fix(chat): classify model refusals instead of generic EmptyLLMResponseError (#13332) to release v4.4 by @evan-onyx in https://github.com/onyx-dot-app/onyx/pull/13634
* fix: hierarchynodes accessible private connectors (#13625) to release v4.4 by @evan-onyx in https://github.com/onyx-dot-app/onyx/pull/13645
* chore: add refusal reasons (#13628) to release v4.4 by @evan-onyx in https://github.com/onyx-dot-app/onyx/pull/13646
* fix: knowledge pane query filters (#13665) to release v4.4 by @evan-onyx in https://github.com/onyx-dot-app/onyx/pull/13671
* feat(llm): admin-selectable API mode for Bifrost (#13642) to release v4.4 by @justin-tahara in https://github.com/onyx-dot-app/onyx/pull/13677
* fix(llm): harden litellm responses bridge for gateway streaming variants (#13668) to release v4.4 by @justin-tahara in https://github.com/onyx-dot-app/onyx/pull/13678


**Full Changelog**: https://github.com/onyx-dot-app/onyx/compare/v4.4.7...v4.4.8