Fix serialize

>  Sentry.Bindings.Cocoa net8.0-maccatalyst17.0 failed with 1 error(s) and 1 warning(s) (2.7s)
>    ApiDefinitions.cs(937,38): warning CS0108: 'SentrySpan.Serialize()' hides inherited member 'SentrySerializable.Serialize()'. Use the new keyword if hiding was intended.
>    /Users/jpnurmi/Projects/sentry/sentry-dotnet/src/Sentry.Bindings.Cocoa/obj/Release/net8.0-maccatalyst17.0/MacCatalyst/Sentry.CocoaSdk/SentrySpan.g.cs(134,36): error CS0108: 'ISentrySpan.Serialize()' hides inherited member 'ISentrySerializable.Serialize()'. Use the new keyword if hiding was intended.

Author: jpnurmi

scripts/generate-cocoa-bindings.ps1

@@ -279,7 +279,7 @@ $Text = $Text -replace '([\[,] )iOS \(', '$1Introduced (PlatformName.iOS, '
 $Text = $Text -replace '(?m)^interface SentryScope', 'partial $&'
 
 # Prefix SentryBreadcrumb.Serialize and SentryScope.Serialize with new (since these hide the base method)
-$Text = $Text -replace '(?m)(^\s*\/\/[^\r\n]*$\s*\[Export \("serialize"\)\]$\s*)(NSDictionary)', '${1}new $2'
+$Text = $Text -replace '(?m)(^\s*\/\/[^\r\n]*$\s*(?:\[Abstract\]\s*)?\[Export \("serialize"\)\]$\s*)(NSDictionary)', '${1}new $2'
 
 $Text = $Text -replace '.*SentryEnvelope .*?[\s\S]*?\n\n', ''
 $Text = $Text -replace '.*typedef.*SentryOnAppStartMeasurementAvailable.*?[\s\S]*?\n\n', ''

src/Sentry.Bindings.Cocoa/ApiDefinitions.cs

@@ -183,7 +183,7 @@ interface SentrySerializable
     // @required -(NSDictionary<NSString *,id> * _Nonnull)serialize;
     [Abstract]
     [Export ("serialize")]
-    NSDictionary<NSString, NSObject> Serialize();
+    new NSDictionary<NSString, NSObject> Serialize();
 }
 
 // @interface SentryBreadcrumb : NSObject <SentrySerializable>
@@ -930,6 +930,11 @@ interface SentrySpan : SentrySerializable
     [Abstract]
     [NullAllowed, Export ("baggageHttpHeader")]
     string BaggageHttpHeader { get; }
+
+    // @required -(NSDictionary<NSString *,id> * _Nonnull)serialize;
+    [Abstract]
+    [Export ("serialize")]
+    new NSDictionary<NSString, NSObject> Serialize();
 }
 
 // @interface SentryHub : NSObject