Increase Max Nanite Program Limit (#7082)

## About The Pull Request
20 -> 50
## Why It's Good For The Game
Lets people do more cool flavorful stuff using skull echos and sensors
and conversation filters and such. All the actual effect programs with
healing and damage are unstackable, so no balance effects.
## Changelog
:cl:
qol: Increases max program limit of nanites from 20 -> 50.
/:cl:

Author: throwawayuseless

code/__DEFINES/nanites.dm

@@ -3,7 +3,7 @@
 #define NANITE_SHOCK_IMMUNE 1
 #define NANITE_EMP_IMMUNE 2
 
-#define NANITE_PROGRAM_LIMIT 20
+#define NANITE_PROGRAM_LIMIT 50
 
 
 #define NANITE_BASE_RESEARCH 3.5