docs/about/emulation: fix typo

Duplicated word "are".

Signed-off-by: Lizhi Yang <sledgeh4w@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230511080119.99018-1-sledgeh4w@gmail.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

docs/about/emulation.rst

@@ -99,7 +99,7 @@ depending on the guest architecture.
     - Yes
     - A configurable 32 bit soft core now owned by Cadence
 
-A number of features are are only available when running under
+A number of features are only available when running under
 emulation including :ref:`Record/Replay<replay>` and :ref:`TCG Plugins`.
 
 .. _Semihosting: