Use npm instead of yarn in workflows

.github/workflows/frontend_lint_and_test.yml

@@ -61,7 +61,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - name: Install modules
-        run: yarn
+        run: npm ci
       - name: Run ESLint
         run: npx eslint . --ext .js,.jsx,.ts,.tsx --max-warnings=0
 
@@ -73,6 +73,6 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - name: Install modules
-        run: yarn
+        run: npm ci
       - name: Run Unused Exports Check
         run: ./node_modules/.bin/ts-unused-exports tsconfig.json