fix install script to handle flang correctly

Author: everythingfunctional

install.sh

@@ -273,6 +273,7 @@ fi
 echo "PKG_CONFIG_PATH=$PKG_CONFIG_PATH"
 
 FPM_FC="$($REALPATH $(command -v $FC))"
+FPM_FC=${FPM_FC/flang-20/flang-new}
 FPM_CC="$($REALPATH $(command -v $CC))"
 
 ask_package_permission()