ci: add setup-uv action to ng-renovate workflow

This is needed as `angular/web-codegen-scorer` uses Python.

```
 Renovate is exiting with a non-zero code due to the following logged errors
       "loggerErrors": [
         {
           "name": "renovate",
           "level": 50,
           "logContext": "7409c965-dd29-4716-9008-218094f5b2ab",
           "repository": "angular/web-codegen-scorer",
           "branch": "ng-renovate/lock-file-maintenance",
           "baseBranch": "main",
           "err": {
             "errno": -2,
             "code": "ENOENT",
             "syscall": "spawn uv",
             "path": "uv",
             "spawnargs": ["lock", "--upgrade"],
             "message": "spawn uv ENOENT",
             "stack": "Error: spawn uv ENOENT\n    at Process.ChildProcess._handle.onexit (node:internal/child_process:286:19)\n    at onErrorNT (node:internal/child_process:484:16)\n    at processTicksAndRejections (node:internal/process/task_queues:89:21)"
           },
           "msg": "unhandledRejection"
         }
       ]
```

Author: alan-agius4

.github/workflows/ng-renovate.yml

@@ -36,6 +36,7 @@ jobs:
           cache-dependency-path: './.github/ng-renovate/pnpm-lock.yaml'
       - run: pnpm install --frozen-lockfile
         working-directory: ./.github/ng-renovate
+      - uses: astral-sh/setup-uv@803947b9bd8e9f986429fa0c5a41c367cd732b41 #v7.2.1
       - run: pnpm exec renovate
         working-directory: ./.github/ng-renovate
         env: