Use ubuntu-latest for macOS result jobs

The result jobs in macOS workflows only check if other jobs failed
(just runs `exit 1`). They don't need macOS runners. Using
ubuntu-latest instead frees up macOS runner slots and starts faster
due to shorter queue times.

Author: st0012

.github/workflows/macos.yml

@@ -175,7 +175,7 @@ jobs:
   result:
     if: ${{ always() }}
     name: ${{ github.workflow }} result
-    runs-on: macos-latest
+    runs-on: ubuntu-latest
     needs: [make]
     steps:
       - run: exit 1

.github/workflows/yjit-macos.yml

@@ -188,7 +188,7 @@ jobs:
   result:
     if: ${{ always() }}
     name: ${{ github.workflow }} result
-    runs-on: macos-14
+    runs-on: ubuntu-latest
     needs: [make]
     steps:
       - name: ${{ github.workflow }} jobs have failed

.github/workflows/zjit-macos.yml

@@ -164,7 +164,7 @@ jobs:
   result:
     if: ${{ always() }}
     name: ${{ github.workflow }} result
-    runs-on: macos-14
+    runs-on: ubuntu-latest
     needs: [make]
     steps:
       - run: exit 1