Bump actions/checkout from 3 to 4 (#7)

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v3...v4)

---
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>

.github/workflows/cmake.yml

@@ -13,7 +13,7 @@ jobs:
       - name: Install dependencies 
         run: sudo apt-get install -y cmake make llvm-dev lld clang libclang-dev
       - name: Checkout Enzyme
-        uses: actions/checkout@v3 
+        uses: actions/checkout@v4 
         with:
           repository: 'EnzymeAD/Enzyme'
           path: 'enzyme'
@@ -24,7 +24,7 @@ jobs:
         working-directory: enzyme/build
         run: sudo make -j `nproc` install        
       - name: Checkout
-        uses: actions/checkout@v3    
+        uses: actions/checkout@v4    
         with:
           path: 'main'
       - name: Configure