Add macOS-13 to CI matrix

Author: bhimrazy

.github/workflows/ci-tests-fabric.yml

@@ -40,6 +40,7 @@ jobs:
       matrix:
         include:
           # only run PyTorch latest
+          - { os: "macOS-13", pkg-name: "lightning", python-version: "3.10", pytorch-version: "2.1" }
           - { os: "macOS-14", pkg-name: "lightning", python-version: "3.10", pytorch-version: "2.1" }
           - { os: "ubuntu-22.04", pkg-name: "lightning", python-version: "3.10", pytorch-version: "2.1" }
           - { os: "windows-2022", pkg-name: "lightning", python-version: "3.10", pytorch-version: "2.1" }