ci_setup_test.sh: set dosemu prefix similar to fdpp

This should fix CI as it seems current landlock rules do not allow
the prefix mismatch.

Author: stsp

ci_setup_test.sh

@@ -39,6 +39,7 @@ fi
   mk-build-deps --install --root-cmd sudo
 
   CC=clang ./default-configure -d \
+    --prefix=${DIR_ROOT}/${DIR_INSTALLED_FDPP} \
     --with-fdpp-lib-dir=${DIR_ROOT}/${DIR_INSTALLED_FDPP}/lib/fdpp \
     --with-fdpp-include-dir=${DIR_ROOT}/${DIR_INSTALLED_FDPP}/include \
     --with-fdpp-pkgconf-dir=${DIR_ROOT}/${DIR_INSTALLED_FDPP}/lib/pkgconfig