Merge pull request The-OpenROAD-Project#3496 from The-OpenROAD-Project-staging/no-gui-no-lib

If GUI_TIMING=0 skip reading Liberty files

Author: maliberty

flow/scripts/open.tcl

@@ -2,7 +2,9 @@ source $::env(SCRIPTS_DIR)/util.tcl
 
 source_env_var_if_exists PLATFORM_TCL
 
-source $::env(SCRIPTS_DIR)/read_liberty.tcl
+if { [env_var_equals GUI_TIMING 1] } {
+  source $::env(SCRIPTS_DIR)/read_liberty.tcl
+}
 
 if { [env_var_exists_and_non_empty DEF_FILE] } {
   log_cmd read_lef $::env(TECH_LEF)