fix(ci): add xvfb for VS Code tests in headless environment

Author: Dante

.github/workflows/ci.yml

@@ -24,7 +24,7 @@ jobs:
         run: npm ci
 
       - name: Run tests
-        run: npm test
+        run: xvfb-run -a npm test
 
       - name: Compile extension
         run: npm run compile

.github/workflows/publish.yml

@@ -23,7 +23,7 @@ jobs:
         run: npm ci
 
       - name: Run tests
-        run: npm test
+        run: xvfb-run -a npm test
 
       - name: Compile extension
         run: npm run compile