chore(deps): bump actions/checkout from 5 to 6 (#200)

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](actions/checkout@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>

Author: dependabot[bot]

.github/workflows/demo.yaml

@@ -8,7 +8,7 @@ jobs:
         working-directory: demo
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Install Java
         uses: actions/setup-java@v5
@@ -45,7 +45,7 @@ jobs:
         working-directory: demo
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Setup Node  
         uses: actions/setup-node@v6

.github/workflows/sdk.yaml

@@ -8,7 +8,7 @@ jobs:
         working-directory: sdk
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Setup Node  
         uses: actions/setup-node@v6
@@ -31,7 +31,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           # Make sure the actual branch is checked out when running on pull requests
           ref: ${{ github.head_ref }}