Update anycubic_i3_mega_s.def.json

Increased max. Extruder Feedrate to match newer firmware

resources/definitions/anycubic_i3_mega_s.def.json

@@ -85,9 +85,9 @@
         "infill_overlap": { "value": 15.0 },
 
 
-        "retraction_speed": { "value": 25, "maximum_value": 40 },
-        "retraction_retract_speed": { "maximum_value": 40 },
-        "retraction_prime_speed": { "maximum_value": 40 },
+        "retraction_speed": { "value": 30, "maximum_value": 60 },
+        "retraction_retract_speed": { "maximum_value": 60 },
+        "retraction_prime_speed": { "maximum_value": 60 },
 
         "retraction_hop_enabled": { "value": true },
         "retraction_hop": { "value": 0.075 },