fix: increase density of Metal3..5 fill

Author: htfab

scripts/add-fill.py

@@ -18,9 +18,9 @@
     ("NWell", (31, 0), 5)],
     [("Metal1", (8, 0), 4)],
     [("Metal2", (10, 0), 4)],
-    [("Metal3", (30, 0), 3)],
-    [("Metal4", (50, 0), 3)],
-    [("Metal5", (67, 0), 2)],
+    [("Metal3", (30, 0), 4)],
+    [("Metal4", (50, 0), 4)],
+    [("Metal5", (67, 0), 4)],
 ]
 
 layout = pya.Layout()