[dotnet] Update CHANGELOG with last changes
v4.0.0
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+ * Prevented getting bodies of responses for redirects, as this causes an
+ error in the DevTools protocol.
+ * (on behalf of Brandon Walderman) Made adding browser-specific options for
+ Chromium-based browsers more obvious.
* (on behalf of Puja Jagani) Added constructor for creating a Cookie instance
with all optional arguments. Fixes issue #9361.
* Add infratructure for future support of previously unsupported interaction
