ci: install serverless version after npm update

Author: Jeff Gordon

.github/workflows/validate.yml

@@ -63,14 +63,14 @@ jobs:
       - name: Install pipenv / poetry / uv
         run: python -m pip install pipenv poetry uv
 
-      - name: Install serverless
-        run: npm install -g serverless@${{ matrix.sls-version }}
-
       - name: Install dependencies
         if: steps.cacheNpm.outputs.cache-hit != 'true'
         run: |
           npm update --no-save
           npm update --save-dev --no-save
+      - name: Install serverless
+        run: npm install -g serverless@${{ matrix.sls-version }}
+
       - name: Validate Prettier formatting
         run: npm run prettier-check:updated
       - name: Validate ESLint rules