Revert mac os CI testing

.github/workflows/regression.yml

@@ -21,26 +21,17 @@ on:
 
 jobs:
   regression:
-    runs-on: ${{ matrix.os }}
+    runs-on: ubuntu-latest
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest, macos-latest]
         CI_NODE_INDEX: [0, 1, 2, 3, 4]
 
     steps:
       - uses: actions/checkout@v4
         with:
           fetch-depth: 0
 
-      - name: Set up firefox for macos
-        if: matrix.os == 'macos-latest'
-        run: |
-          brew install firefox
-          # Install GNU grep to use 'grep -P'
-          brew install grep
-          echo "/opt/homebrew/opt/grep/libexec/gnubin" >> $GITHUB_PATH
-
       - name: Set up Node.js
         uses: actions/setup-node@v4
         with: