Add JSON to code block (#3885)

Co-authored-by: Suchintan Singh <suchintan@skyvern.com>

skyvern/forge/sdk/workflow/models/block.py

@@ -1516,6 +1516,7 @@ class CodeBlock(Block):
             "bool": bool,
             "asyncio": asyncio,
             "re": re,
+            "json": json,
             "Exception": Exception,
         }