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

Author: dependabot[bot]

.github/workflows/main.yml

@@ -13,7 +13,7 @@ jobs:
         os: [ubuntu-latest, macos-latest, windows-latest]
     runs-on: ${{ matrix.os }}
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
       with:
         submodules: true
     - uses: goto-bus-stop/setup-zig@v1