remove redundant word

README.md

@@ -96,7 +96,7 @@ In general, use panics for bad states that are unreachable, unrecoverable or har
 For those caused by invalid user input, however, we prefer to report that invalidity
 gracefully as an error result instead of panicking. In general, invalid input should result
 in an `Error` as soon as possible. It *is* ok for code paths after validation to assume validation has 
-already occurred and and panic if not. See [this ticket] for more nuances.
+already occurred and panic if not. See [this ticket] for more nuances.
 
 [this ticket]: https://github.com/apache/arrow-rs/issues/6737