Bump actions/checkout from 2 to 3 (#576)

Bumps [actions/checkout](https://github.com/actions/checkout) from 2 to 3.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v2...v3)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/CI.yml

@@ -26,7 +26,7 @@ jobs:
     env:
       PYTHON: ""
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: julia-actions/setup-julia@v1
         with:
           version: ${{ matrix.version }}

.github/workflows/Documenter.yml

@@ -14,7 +14,7 @@ jobs:
         with:
           version: '1'
           show-versioninfo: true         # print versioninfo in the action log
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: julia-actions/julia-buildpkg@latest
       - uses: julia-actions/julia-docdeploy@latest
         env:

.github/workflows/check_builtins.yml

@@ -10,7 +10,7 @@ jobs:
     name: 'Check builtins.jl consistency'
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: julia-actions/setup-julia@v1
         with:
           version: nightly