Update testing.yml

Author: jGaboardi

.github/workflows/testing.yml

@@ -41,9 +41,9 @@
            - ci/313-numba-dev.yaml
          include:
            - environment-file: ci/313-numba-latest.yaml
-             os: macos-13 # Intel
+             os: macos-15-intel # Intel
            - environment-file: ci/313-numba-latest.yaml
-             os: macos-14 # Apple Silicon
+             os: macos-latest # Apple Silicon
            - environment-file: ci/313-numba-latest.yaml
              os: windows-latest
        fail-fast: false