run only a single build on each platform

Author: JacksonBurns

.github/workflows/conda_build.yml

@@ -18,6 +18,27 @@ jobs:
         os: [ubuntu-latest, macos-15-intel, macos-latest]
         numpy-version: ["1.26"]
         python-version: ["3.9", "3.10", "3.11"]
+        event_name: ["${{ contains(github.event_name, 'pull_request') }}"]
+        exclude:
+        # for PRs just run a single build per platform to save time and resources
+          - event_name: true
+            os: ubuntu-latest
+            python-version: "3.9"
+          - event_name: true
+            os: ubuntu-latest
+            python-version: "3.10"
+          - event_name: true
+            os: macos-15-intel
+            python-version: "3.9"
+          - event_name: true
+            os: macos-15-intel
+            python-version: "3.10"
+          - event_name: true
+            os: macos-latest
+            python-version: "3.9"
+          - event_name: true
+            os: macos-latest
+            python-version: "3.10"
     runs-on: ${{ matrix.os }}
     name: Build ${{ matrix.os }} Python ${{ matrix.python-version }} Numpy ${{ matrix.numpy-version }}
     defaults: