Bump macOS version of intel github runner

https://github.blog/changelog/2025-09-19-github-actions-macos-13-runner-image-is-closing-down/

Author: qvacua

.github/workflows/build-universal-neovim.yml

@@ -10,9 +10,9 @@ jobs:
     strategy:
       fail-fast: true
       matrix:
-        runner: [ macos-13, macos-14 ]
+        runner: [ macos-14-large, macos-14 ]
         include:
-          - runner: macos-13
+          - runner: macos-14-large
             arch: x86_64
           - runner: macos-14
             arch: arm64