chore(deps): update pnpm/action-setup action to v6

Author: renovate[bot]

.github/workflows/build.yml

@@ -13,7 +13,7 @@ jobs:
     steps:
       - uses: actions/checkout@v6
       - uses: catppuccin/setup-whiskers@v2.0.0
-      - uses: pnpm/action-setup@v4
+      - uses: pnpm/action-setup@v6
       - uses: actions/setup-node@v6
         with:
           cache: pnpm

.github/workflows/release-please.yml

@@ -30,7 +30,7 @@ jobs:
     if: ${{ needs.release-please.outputs.release_created }}
     steps:
       - uses: actions/checkout@v6
-      - uses: pnpm/action-setup@v4
+      - uses: pnpm/action-setup@v6
       - uses: actions/setup-node@v6
         with:
           cache: pnpm