It appears that not all testcases are adapted for macos-15 yet, so for now use macos-14

Author: jan.nijtmans

.github/workflows/mac-build.yml

@@ -13,7 +13,7 @@ env:
   ERROR_ON_FAILURES: 1
 jobs:
   xcode:
-    runs-on: macos-15
+    runs-on: macos-14
     defaults:
       run:
         shell: bash
@@ -57,7 +57,7 @@ jobs:
           fi
         timeout-minutes: 30
   clang:
-    runs-on: macos-15
+    runs-on: macos-14
     strategy:
       matrix:
         symbols: