Remove the second source path definition from the CMake command

The '%cmake' RPM macro in Fedora actually expands to:
| ...
|   /usr/bin/cmake \
|         -S "." \
|         -B "redhat-linux-build" \
| ...

So in this case the source patch was specified twice.
First in the macro with the '-S' option and second time outside of the macro,
in the SPECfile, without the '-S' option.

CMake upstream declares that:
|  This has never been officially documented or supported,
|  but older versions accidentally accepted multiple source paths
|  and used the last path specified. Update scripts to avoid
|  passing multiple source path arguments.
https://cmake.org/cmake/help/v3.23/release/3.23.html#deprecated-and-removed-features

This was discovered as CMake upstream implemented a change to the 3.23.0-rc2 release
that changed this behavior and it broke many Fedora packages that used this
double source path definition.
  See rhbz#2057738 to see how build behaved

After the CMake upstream got aware of what problems it caused in Fedora,
they opened a merge request to restore the behavior to the old one,
but kept the warnings that that is an unsupported and problematic behavior:
  https://gitlab.kitware.com/cmake/cmake/-/issues/23334

--

Related: #2092371 #2092370

galera.spec

@@ -40,7 +40,7 @@ replication engine see http://www.codership.com.
 %{set_build_flags}
 
 
-%cmake . \
+%cmake \
        -DCMAKE_BUILD_TYPE="%{?with_debug:Debug}%{!?with_debug:RelWithDebInfo}" \
        -DINSTALL_LAYOUT=RPM \
        -DCMAKE_RULE_MESSAGES:BOOL=OFF \