Add missing availability annotation on publicKeyData. (#36135)

Author: bzbarsky-apple

src/darwin/Framework/CHIP/MTRCertificateInfo.h

@@ -68,7 +68,7 @@ MTR_AVAILABLE(ios(16.4), macos(13.3), watchos(9.4), tvos(16.4))
 /**
  * Public key data for this certificate
  */
-@property (nullable, readonly, retain) NSData * publicKeyData;
+@property (nullable, readonly, retain) NSData * publicKeyData MTR_NEWLY_AVAILABLE;
 
 @end