workflows/tests: tweak PATH setup.

.github/workflows/tests.yml

@@ -13,8 +13,13 @@ jobs:
     steps:
     - name: Set up Git repository
       uses: actions/checkout@v1
-    - name: Add Homebrew path
-      run: echo "::add-path::/home/linuxbrew/.linuxbrew/bin:/usr/local/bin:/usr/bin:/bin"
+    - name: Set up Homebrew PATH
+      run: |
+        if [ "$RUNNER_OS" = "macOS" ]; then
+          echo "::add-path::/usr/local/bin:/usr/bin:/bin"
+        else
+          echo "::add-path::/home/linuxbrew/.linuxbrew/bin:/usr/bin:/bin"
+        fi
       
     - name: Set up Homebrew
       run: |