App crashes when leaving a Brave Talk call

[kylehickinson]

Description:

Small regression in https://github.com/brave/brave-ios/pull/8306

Steps to Reproduce

1. Launch native talk via talk.brave.com
2. End the call or close before entering the call

Reproduces how often:

Always

Brave Version: 1.60+

[Uni-verse]

Verified on iPhone 12 running iOS 17.1.1 using version 1.60 (23.11.20.17)

• Verified crash is not reproducible using STR in https://github.com/brave/brave-ios/issues/8446#issue-2002466384.
• Verified ending brave talk call or closing before entering the call does not cause crash.
• Verified crash does not happen on fresh and upgrading profiles.