ci: use hash to install setup-uv action

Author: cpcloud

.github/workflows/bandit.yml

@@ -23,7 +23,7 @@ jobs:
         uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8  # v5.0.0
 
       - name: Install uv
-        uses: astral-sh/setup-uv@v6
+        uses: astral-sh/setup-uv@b75a909f75acd358c2196fb9a5f1299a9a8868a4  # v6.7.0
 
       - name: Get ignore codes
         id: ignore-codes