docs: remove typo in README.md

Author: stainless-app[bot]

README.md

@@ -140,8 +140,6 @@ The SDK throws custom unchecked exception types:
 
 Additionally, all 4xx errors inherit from `Orb4xxException`.
 
-false
-
 - `OrbIOException`: I/O networking errors.
 
 - `OrbInvalidDataException`: Failure to interpret successfully parsed data. For example, when accessing a property that's supposed to be required, but the API unexpectedly omitted it from the response.