build: cache node_modules in CI

.github/workflows/build.yml

@@ -20,8 +20,15 @@ jobs:
           node-version: '20'
           cache: 'yarn'
 
-      # TODO cache
+      - name: Cache node_modules
+        id: install-cache
+        uses: actions/cache@v4
+        with:
+          path: 'node_modules'
+          key: ${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+
       - name: Install
+        if: steps.install-cache.outputs.cache-hit != 'true'
         run: yarn install --frozen-lockfile
 
       - name: Build
@@ -30,7 +37,6 @@ jobs:
       - name: Lint
         run: yarn lint
 
-      # TODO Run as separate job? Only when Install is cached
       - name: Test
         run: yarn test:ci