Add minimum requirements to CHANGELOG.md (#10628)

* Add minimum requirements to CHANGELOG.md

- add gtk 3.8
- add glibc_2.34
- add MacOS 11

* Casing

* Add to changed section

* Update CHANGELOG.md

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Co-authored-by: Christoph <siedlerkiller@gmail.com>

CHANGELOG.md

@@ -21,6 +21,7 @@ Note that this project **does not** adhere to [Semantic Versioning](https://semv
 - The two previews in the change resolver dialog now have their scrollbars synchronized. [#9576](https://github.com/JabRef/jabref/issues/9576).
 - We changed the setting of the keyword separator to accept a single character only. [#177](https://github.com/koppor/jabref/issues/177)
 - Short DOI formatter now checks, if the value is already formatted. If so, it returns the value instead of calling the ShortDOIService again. [#10589](https://github.com/JabRef/jabref/issues/10589)
+- We upgraded to JavaFX 21.0.1. As a consequence JabRef requires now macOS 11 or later and GTK 3.8 or later on Linux [10627](https://github.com/JabRef/jabref/pull/10627).
 
 ### Fixed