Bump actions/checkout from 2 to 6 (#1246)

Bumps [actions/checkout](https://github.com/actions/checkout) from 2 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v2...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/Formatter.yml

@@ -10,7 +10,7 @@ jobs:
     name: "Format Check"
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v6
       - uses: julia-actions/setup-julia@v3
         with:
           version: 1

.github/workflows/ci.yml

@@ -35,7 +35,7 @@ jobs:
           - x64
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Setup Julia
         uses: julia-actions/setup-julia@v3
@@ -69,7 +69,7 @@ jobs:
     continue-on-error: true
     steps:
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v6
 
       - name: Setup julia
         uses: julia-actions/setup-julia@v3