fix(iOS): Remove insecure ATS exception for localhost and enforce secure defaults

[subhankarmaiti]

This PR addresses a security issue raised by the Semgrep scan regarding the use of NSExceptionAllowsInsecureHTTPLoads under the NSExceptionDomains configuration for localhost in example/ios/Auth0Example/Info.plist.

Issue

Semgrep reported an Insecure App Transport Security (ATS) exception, allowing unencrypted HTTP traffic for localhost, which violates recommended security practices.

Findings:

• NSExceptionAllowsInsecureHTTPLoads was set to true
• No NSExceptionMinimumTLSVersion or NSExceptionRequiresForwardSecrecy was enforced

Mitigation

As per the recommendation:

• Removed NSExceptionDomains entry for localhost
• Ensured that NSAllowsArbitraryLoads is explicitly set to false
• Enabled NSAllowsLocalNetworking to preserve support for local development/test environments

Impact

• No functional impact expected since local development will still work due to NSAllowsLocalNetworking.
• Enhances security posture and satisfies Semgrep SAST policy.