Update pnpm/action-setup action to v6

Author: renovate[bot]

.github/workflows/test_ci.yml

@@ -12,7 +12,7 @@ jobs:
     steps:
       - uses: actions/checkout@v6
 
-      - uses: pnpm/action-setup@v4
+      - uses: pnpm/action-setup@v6
 
       - uses: actions/setup-node@v6
         with: