Reduce macos runs in main.yml (onnx#7076)

### Description
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### Motivation and Context
<!-- - Why is this change required? What problem does it solve? -->
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Signed-off-by: Andreas Fehlner <fehlner@arcor.de>
Signed-off-by: Justin Chu <justinchuby@users.noreply.github.com>
Co-authored-by: Justin Chu <justinchuby@users.noreply.github.com>

Author: andife

.github/workflows/main.yml

@@ -89,6 +89,13 @@ jobs:
             python_version: '3.9'
           - os: windows-latest # TODO: reevalute for final python 3.14 release: "Numpy built with MINGW-W64 on Windows 64 bits is experimental"
             python_version: '3.14-dev'
+          # skip mac os 3.9, 3.11, 3.13
+          - os:  macos-latest
+            python_version: '3.9'
+          - os:  macos-latest
+            python_version: '3.11'
+          - os:  macos-latest
+            python_version: '3.13'
 
     runs-on: ${{ matrix.os }}
     steps: