ci: upgrade pnpm/action-setup to v6 for Node.js 24 compatibility

v4 still runs on Node.js 20, causing deprecation warnings.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: theothersideofgod

.github/workflows/ci.yaml

@@ -21,7 +21,7 @@ jobs:
         uses: actions/checkout@v5
 
       - name: Setup pnpm
-        uses: pnpm/action-setup@v4
+        uses: pnpm/action-setup@v6
 
       - name: Setup Node.js
         uses: actions/setup-node@v5

.github/workflows/test-k8s-deployment.yaml

@@ -68,7 +68,7 @@ jobs:
         uses: actions/checkout@v5
 
       - name: Setup pnpm
-        uses: pnpm/action-setup@v4
+        uses: pnpm/action-setup@v6
 
       - name: Setup Node.js
         uses: actions/setup-node@v5

.github/workflows/test.yaml

@@ -17,7 +17,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v5
-      - uses: pnpm/action-setup@v4
+      - uses: pnpm/action-setup@v6
       - uses: actions/setup-node@v5
         with:
           node-version: '22'
@@ -31,7 +31,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v5
-      - uses: pnpm/action-setup@v4
+      - uses: pnpm/action-setup@v6
       - uses: actions/setup-node@v5
         with:
           node-version: '22'