Use macos-15-intel (#18)

Author: jaimergp

.github/workflows/test.yml

@@ -31,9 +31,9 @@ jobs:
         os: [ubuntu-latest, windows-latest]
         python-version: ["39", "310", "311", "312"]
         include:
-          - os: macos-13
+          - os: macos-15-intel
             python-version: "39"
-          - os: macos-14
+          - os: macos-latest
             python-version: "312"
     env:
       PIXI_ENV_NAME: test-py${{ matrix.python-version }}