[CI] pin setup-uv action to commit hash

Author: trendels

.github/workflows/build.yml

@@ -25,7 +25,7 @@ jobs:
           persist-credentials: false
 
       - name: Install uv
-        uses: astral-sh/setup-uv@v6
+        uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba  # v6.3.1
         with:
           python-version: ${{ matrix.python-version }}
           enable-cache: true