flow: update rules

Signed-off-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: github-actions[bot]

flow/designs/sky130hs/ibex/rules-base.json

@@ -52,7 +52,7 @@
         "compare": ">="
     },
     "globalroute__timing__setup__tns": {
-        "value": -35.7,
+        "value": -54.1,
         "compare": ">="
     },
     "globalroute__timing__hold__ws": {