fix workflow

Author: twishabansal

.github/workflows/skills-validate.yml

@@ -33,21 +33,14 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - name: Checkout agentskills/agentskills
-        uses: actions/checkout@v4
-        with:
-          repository: agentskills/agentskills
-          path: agentskills
-
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
           python-version: "3.11"
 
       - name: Install skills-ref
         run: |
-          cd agentskills/skills-ref
-          pip install .
+          pip install "git+https://github.com/agentskills/agentskills.git#subdirectory=skills-ref"
 
       - name: Validate Skills
         run: |