perf(ci): cache composer vendor and npm dependencies in Cypress init job

Adds buildjet/cache for composer vendor/ (keyed on composer.lock) and
enables setup-node's built-in npm cache so the init job skips full
reinstalls when lock files haven't changed between runs.

Signed-off-by: Anna Larch <anna@larch.dev>
AI-Assisted-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Signed-off-by: Anna Larch <anna@nextcloud.com>

Author: Anna Larch

.github/workflows/cypress.yml

@@ -54,6 +54,15 @@ jobs:
         with:
           files: 'composer.json'
 
+      - name: Cache composer dependencies
+        if: steps.check_composer.outputs.files_exists == 'true'
+        uses: buildjet/cache@3e70d19e31d6a8030aeddf6ed8dbe601f94d09f4 # v4.0.2
+        with:
+          path: vendor
+          key: ${{ runner.os }}-composer-${{ hashFiles('composer.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-composer-
+
       - name: Install composer dependencies
         if: steps.check_composer.outputs.files_exists == 'true'
         run: composer install --no-dev
@@ -69,6 +78,7 @@ jobs:
         uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
         with:
           node-version: ${{ steps.versions.outputs.nodeVersion }}
+          cache: 'npm'
 
       - name: Set up npm ${{ steps.versions.outputs.npmVersion }}
         run: npm i -g 'npm@${{ steps.versions.outputs.npmVersion }}'