ci: bump checkout / setup-node / pnpm-action-setup to v6

Node 20 is being deprecated on GitHub-hosted runners (forced to Node 24
on 2026-06-02). v6 of these actions ships on Node 24.

Author: YunYouJun

.github/workflows/ci.yml

@@ -15,11 +15,11 @@ jobs:
   lint:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
-      - uses: pnpm/action-setup@v4
+      - uses: pnpm/action-setup@v6
 
-      - uses: actions/setup-node@v4
+      - uses: actions/setup-node@v6
         with:
           node-version: lts/*
           cache: pnpm

.github/workflows/release.yml

@@ -12,15 +12,15 @@ jobs:
       contents: write
       id-token: write
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
 
       - name: Install pnpm
-        uses: pnpm/action-setup@v4
+        uses: pnpm/action-setup@v6
 
       - name: Use Node.js LTS
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@v6
         with:
           node-version: lts/*
           registry-url: https://registry.npmjs.org/