[doc][handbook] remove description for the test_dumux.sh

doc/handbook/2_quickinstall.tex

@@ -59,12 +59,4 @@ paraview *pvd
 (green double arrow on top right) to admire the colorful pressure distribution.
 \end{enumerate}
 
-These commands are compiled into \texttt{test\_dumux.sh}, which you can download and run
-from the same directory from which you ran \texttt{installdumux.py}.
-
-\begin{lstlisting}[style=Bash,escapechar=\%]
-$ wget https://git.iws.uni-stuttgart.de/dumux-repositories/dumux/-/raw/releases/%\DumuxVersion%/bin/util/test_dumux.sh
-$ wget sh test_dumux.sh
-\end{lstlisting}
-
 For further information on how to get started with dumux, see section \ref{chp:tutorial}.