Cmake: Sets minimum macOS SDK and XCode to 26.1.

[danrossi]

Description

There is a build issue in macOS with errors if the Xcode and Swift version is too old. This cmake config change sets the minimum macOS SDK and XCode version to 26.1. To match the CI mac build environment. XCode 16.3 builds but best to match the CI build system. This requires macOS 15.6 and above.

I am unable to find the docs for building the source.

Motivation and Context

Related: #13384

This fixes a build error when using macOS 14 and Xcode 16.1.

How Has This Been Tested?

cmake --preset macos
cd build_macos
xcodebuild                                                 \
  -configuration RelWithDebInfo \
  -scheme obs-studio                                       \
  -parallelizeTargets                                      \
  -destination "generic/platform=macOS,name=Any Mac"

Types of changes

Bug fix (non-breaking change which fixes an issue)

Checklist:

• [ x] I have read the contributing document.
• My code has been run through clang-format.
• [ x] My code follows the project's style guidelines
• [ x] My code is not on the master branch.
• [ x] My code has been tested.
• [ x] All commit messages are properly formatted and commits squashed where appropriate.
• I have included updates to all appropriate documentation.

[danrossi]

The checks is still happening. However with an XCode Universal 26.1. A Universal build can be made on arm64. I am not sure what XCode the x86 has.

OBS builds a universal build. So any XCode 26.1 and above that doesn't say Apple Silicon is the Universal XCode. It needs to be manually installed via this site or Xcodes. As the Apple Store was only offering 16.1.

https://xcodereleases.com/