ci: add missing shell property to composite action

.github/actions/prepare/action.yml

@@ -3,14 +3,11 @@ description: Setup environment
 runs:
   using: 'composite'
   steps:
-    - name: Checkout
-      uses: actions/checkout@v4
-      with:
-        fetch-depth: 0
     - name: Setup NodeJS
       uses: actions/setup-node@v3
       with:
         node-version: '18.x'
         cache: 'npm'
     - name: Install dependencies
       run: npm ci
+      shell: bash