macOS package: fix warning about supported Octave version

In 0c77f7e9, the supported Octave version has
been changed from the Homebrew binary to the standalone application.

However, the runtime check about the supported Octave version was not updated,
and was still pointing to the Homebrew version number.

macOS/build.sh

@@ -166,7 +166,7 @@ PATH="$OCTAVE_BIN_DIR:$PATH" CC=$CC CXX=$CXX ./configure \
   --with-slicot="$LIB64"/Slicot/with-underscore
 PATH="$OCTAVE_BIN_DIR:$PATH" make -j"$NTHREADS"
 cp -L  "$ROOTDIR"/mex/octave/*                                       "$PKGFILES"/mex/octave
-echo -e "function v = supported_octave_version\nv=\"$(octave --eval "disp(OCTAVE_VERSION)")\";\nend" > "$PKGFILES"/matlab/supported_octave_version.m
+echo -e "function v = supported_octave_version\nv=\"$OCTAVE_VERSION\";\nend" > "$PKGFILES"/matlab/supported_octave_version.m
 
 
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