move to macos-15-intel runner (#561)

Author: taniabogatsch

.github/workflows/tests.yaml

@@ -13,7 +13,7 @@ jobs:
         shell: bash
     strategy:
       matrix:
-        os: [ubuntu-latest, macos-latest, windows-latest, macos-13, ubuntu-24.04-arm]
+        os: [ubuntu-latest, macos-latest, windows-latest, macos-15-intel, ubuntu-24.04-arm]
         go: [1.24]
       fail-fast: false
     steps:
@@ -69,9 +69,9 @@ jobs:
     strategy:
       matrix:
         go: [1.24]
-        os: [macos-13, macos-14, ubuntu-latest, ubuntu-24.04-arm]
+        os: [macos-15-intel, macos-14, ubuntu-latest, ubuntu-24.04-arm]
         include:
-          - os: "macos-13"
+          - os: "macos-15-intel"
             filename: "libduckdb-osx-universal"
             ld_path_env_name: "DYLD_LIBRARY_PATH"
           - os: "macos-14"