fix: iOS native bridge option creation

[bitsandfoxes]

Fixes an issue reported in #1951 (comment)

<REDACTED>/data/jenkins/workspace/<REDACTED>/iOS/Build/iOS/Libraries/io.sentry.unity/SentryNativeBridge.m:37:9: error: performSelector names a selector which retains the object
   37 |         performSelector:@selector(initWithDict:didFailWithError:)
      |         ^
In module 'Sentry' imported from <REDACTED>/data/jenkins/workspace/<REDACTED>/iOS/Build/iOS/Libraries/io.sentry.unity/SentryNativeBridge.m:1:
<REDACTED>/Library/Developer/Xcode/DerivedData/Unity-iPhone-cseycvbiwfelbyekvlwxliadxfvi/Build/Intermediates.noindex/ArchiveIntermediates/Unity-iPhone/BuildProductsPath/Release-iphoneos/Sentry.framework/PrivateHeaders/SentryOptions+HybridSDKs.h:11:1: note: method 'initWithDict:didFailWithError:' declared here
   11 | - (_Nullable instancetype)initWithDict:(NSDictionary<NSString *, id> *)options
      | ^
1 error generated.

If I read that correctly, then this is due to the performSelector not respecting ARC rules properly.
Instead, we're creating the options now directly.

[brustolin]

LGTM

[bitsandfoxes]

Superseded by #1964