chore: remove yarn

Author: titanism

.github/workflows/unit-tests.yaml

@@ -11,5 +11,5 @@ jobs:
       - uses: actions/setup-node@v3
         with:
           node-version: ${{ matrix.node-version }}
-      - run: yarn install --frozen-lockfile
+      - run: npm install
       - run: npm run test-ci