chore(deps): bump actions/checkout from 5 to 6 (#3306)

Bumps [actions/checkout](https://github.com/actions/checkout) from 5 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v5...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Daishi Kato <dai-shi@users.noreply.github.com>

.github/workflows/compressed-size.yml

@@ -6,7 +6,7 @@ jobs:
   compressed_size:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: pnpm/action-setup@v4
       - uses: actions/setup-node@v6
         with:

.github/workflows/preview-release.yml

@@ -6,7 +6,7 @@ jobs:
   preview_release:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: pnpm/action-setup@v4
       - uses: actions/setup-node@v6
         with:

.github/workflows/publish.yml

@@ -8,7 +8,7 @@ jobs:
   publish:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: pnpm/action-setup@v4
       - uses: actions/setup-node@v6
         with:

.github/workflows/test-multiple-builds.yml

@@ -15,7 +15,7 @@ jobs:
         build: [cjs, esm]
         env: [development] # [development, production]
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: pnpm/action-setup@v4
       - uses: actions/setup-node@v6
         with:

.github/workflows/test-multiple-versions.yml

@@ -22,7 +22,7 @@ jobs:
           - 19.2.0-canary-0bdb9206-20250818
           - 0.0.0-experimental-0bdb9206-20250818
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: pnpm/action-setup@v4
       - uses: actions/setup-node@v6
         with:

.github/workflows/test-old-typescript.yml

@@ -29,7 +29,7 @@ jobs:
           - 4.6.4
           - 4.5.5
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: pnpm/action-setup@v4
       - uses: actions/setup-node@v6
         with:

.github/workflows/test.yml

@@ -10,7 +10,7 @@ jobs:
   test:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: pnpm/action-setup@v4
       - uses: actions/setup-node@v6
         with: