[EC-497] Fix memory leaks in tests (#3421)

* Add isolatedModules:true

* Add manual typechecking in CI for libs/ tests

.github/workflows/test.yml

@@ -42,7 +42,16 @@ jobs:
       - name: Install Node dependencies
         run: npm ci
 
+      # We use isolatedModules: true which disables typechecking in tests
+      # Tests in apps/ are typechecked when their app is built, so we just do it here for libs/
+      # See https://bitwarden.atlassian.net/browse/EC-497
+      - name: Run typechecking
+        run: |
+          for p in libs/**/tsconfig.spec.json; do
+            echo "Typechecking $p"
+            npx tsc --noEmit --project $p
+          done
+
       - name: Run tests
         run: |
-          export NODE_OPTIONS=--max_old_space_size=6144
           npm run test