Use Xcode 26.4 for testing and release builds (#6571)

Author: SimplyDanny

.github/workflows/release.yml

@@ -13,7 +13,7 @@ on:
         type: string
 
 env:
-  DEVELOPER_DIR: /Applications/Xcode_26.0.1.app
+  DEVELOPER_DIR: /Applications/Xcode_26.4.app
   RELEASE_BRANCH: release/${{ inputs.version }}
   MIMALLOC_VERSION: 3.0.10
 

.github/workflows/test.yml

@@ -46,7 +46,7 @@ jobs:
           - macOS: '15'
             xcode: '16.4'
           - macOS: '26'
-            xcode: '26.0'
+            xcode: '26.4'
     env:
       DEVELOPER_DIR: /Applications/Xcode_${{ matrix.xcode }}.app
     steps: