Core: Put the dev requirement back in the dev requirements file

Author: ikelos

requirements-dev.txt

@@ -16,7 +16,7 @@ pycryptodome
 
 # This can improve error messages regarding improperly configured ISF files,
 # but is only recommended for development
-# jsonschema>=2.3.0
+jsonschema>=2.3.0
 
 # This is required for memory acquisition via leechcore/pcileech.
 leechcorepyc>=2.4.0