frontend: Allow Stream Delay with multitrack video

[lexano-ivs]

Description

Remove Stream Delay from the incompatible settings list for multitrack video as it works properly now.

Motivation and Context

Stream Delay was incompatible with Enhanced Broadcasting during early development, along with some other standard OBS features, which led to the creation of a MultitrackVideoOutput::HandleIncompatibleSettings() function to notify users and block the stream attempt. Stream Delay compatibility with Enhanced Broadcasting has been tested within the TEB beta and has been working reliably for several months. As a result, we can safely remove Stream Delay from the incompatible function.

How Has This Been Tested?

Tested in the TEB beta for several months, and also local testing on Linux and Windows.

Types of changes

• Tweak (non-breaking change to improve existing functionality)

Checklist:

• My code has been run through clang-format.
• I have read the contributing document.
• My code is not on the master branch.
• The code has been tested.
• All commit messages are properly formatted and commits squashed where appropriate.
• I have included updates to all appropriate documentation.