News in 3.21.2
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* Make gtk_source_style_apply() public
* GtkSourceSearchContext: add "version 2" of some functions to improve the API,
  and deprecate the v1's.
* Fix a critical message when showing a completion window
* Fix a drawing issue with syntax highlighting
* Improvements to the syntax highlighting of: Meson, JavaScript
* Various code improvements and bug fixes
* Documentation improvements
* Build fixes on ARM