improve code block failure reason (#1910)

Co-authored-by: lawyzheng <lawyzheng1106@gmail.com>
Co-authored-by: ellipsis-dev[bot] <65095814+ellipsis-dev[bot]@users.noreply.github.com>

skyvern/forge/sdk/workflow/exceptions.py

@@ -139,3 +139,10 @@ class InsecureCodeDetected(SkyvernException):
         super().__init__(
             f"Insecure code detected. Reason: {msg}",
         )
+
+
+class CustomizedCodeException(SkyvernException):
+    def __init__(self, exception: Exception) -> None:
+        super().__init__(
+            f"Failed to execute code block. Reason: {exception.__class__.__name__}: {str(exception)}",
+        )