docs: Note edge case for macOS 26 (#37392)

versecafe created 

- I believe this is caused by metal not being found due to it being on
the XcodeBeta path, not sure if there's a better fix for this but it'll
work until 26 is the latest release

Release Notes:

- N/A

Change summary

crates/gpui/README.md         | 2 +-
docs/src/development/macos.md | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

Detailed changes

crates/gpui/README.md 🔗 

@@ -23,7 +23,7 @@ On macOS, GPUI uses Metal for rendering. In order to use Metal, you need to do t
 
 - Install [Xcode](https://apps.apple.com/us/app/xcode/id497799835?mt=12) from the macOS App Store, or from the [Apple Developer](https://developer.apple.com/download/all/) website. Note this requires a developer account.
 
-> Ensure you launch XCode after installing, and install the macOS components, which is the default option.
+> Ensure you launch Xcode after installing, and install the macOS components, which is the default option. If you are on macOS 26 (Tahoe) you will need to use `--features gpui/runtime_shaders` or add the feature in the root `Cargo.toml`
 
 - Install [Xcode command line tools](https://developer.apple.com/xcode/resources/)

docs/src/development/macos.md 🔗 

@@ -10,7 +10,7 @@ Clone down the [Zed repository](https://github.com/zed-industries/zed).
 
 - Install [Xcode](https://apps.apple.com/us/app/xcode/id497799835?mt=12) from the macOS App Store, or from the [Apple Developer](https://developer.apple.com/download/all/) website. Note this requires a developer account.
 
-> Ensure you launch Xcode after installing, and install the macOS components, which is the default option.
+> Ensure you launch Xcode after installing, and install the macOS components, which is the default option. If you are on macOS 26 (Tahoe) you will need to use `--features gpui/runtime_shaders` or add the feature in the root `Cargo.toml`
 
 - Install [Xcode command line tools](https://developer.apple.com/xcode/resources/)