Update unit_tests.yml

Author: AntonisZks

.github/workflows/unit_tests.yml

@@ -4,18 +4,23 @@ on:
   push:
     branches:
       - 'main'
-    pull_request:
-      branches:
-        - 'main'
+  pull_request:
+    branches:
+      - 'main'
 
 jobs:
   tests:
-    runs-on: ubuntu-latest, windows-latest, macos-latest
+    runs-on: ubuntu-latest
 
     steps:
       - name: Checkout code
         uses: actions/checkout@v2
 
+      - name: Setup Node
+        uses: actions/setup-node@v2
+        with:
+          node-version: 16.18
+
       - name: Compile Code
         run:
           make all