fix: use jlpm instead of jlpm install in CI spell-check job

The jlpm command without arguments automatically runs yarn install.
This matches the pattern used in build.yml and fixes the 'jlpm: command not found' error.

Author: devin-ai-integration[bot]

.github/workflows/ci.yaml

@@ -22,7 +22,7 @@ jobs:
         uses: jupyterlab/maintainer-tools/.github/actions/base-setup@v1
 
       - name: Install dependencies
-        run: jlpm install
+        run: jlpm
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}