Fix/dupe state (#974)

Co-authored-by: bryceknz <25199713+bryceknz@users.noreply.github.com>

Author: fant0mex

.changeset/cuddly-rules-behave.md

@@ -0,0 +1,5 @@
+---
+'react-native-app-auth': patch
+---
+
+Remove duplicate iOS auth `state` and `nonce` parameters.

packages/react-native-app-auth/ios/RNAppAuth.m

@@ -338,6 +338,10 @@ - (void)authorizeWithConfiguration: (OIDServiceConfiguration *) configuration
     NSString *codeVerifier = usePKCE ? [[self class] generateCodeVerifier] : nil;
     NSString *codeChallenge = usePKCE ? [[self class] codeChallengeS256ForVerifier:codeVerifier] : nil;
     NSString *nonce =  useNonce ? additionalParameters[@"nonce"]? additionalParameters[@"nonce"]:  [[self class] generateState] : nil ;
+    
+    NSMutableDictionary* mutableDict = [additionalParameters mutableCopy];
+    [mutableDict removeObjectForKey:@"state"];
+    [mutableDict removeObjectForKey:@"nonce"];
 
     // builds authentication request
     OIDAuthorizationRequest *request =
@@ -353,7 +357,7 @@ - (void)authorizeWithConfiguration: (OIDServiceConfiguration *) configuration
                                               codeVerifier:codeVerifier
                                              codeChallenge:codeChallenge
                                       codeChallengeMethod: usePKCE ? OIDOAuthorizationRequestCodeChallengeMethodS256 : nil
-                                      additionalParameters:additionalParameters];
+                                      additionalParameters:[mutableDict copy]];
 
     // performs authentication request
     id<UIApplicationDelegate, RNAppAuthAuthorizationFlowManager> appDelegate = (id<UIApplicationDelegate, RNAppAuthAuthorizationFlowManager>)[UIApplication sharedApplication].delegate;