docs: update README.md (#79)

Author: jeffreytse

README.md

@@ -82,10 +82,10 @@ jobs:
   build_and_deploy:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       # Use GitHub Actions' cache to cache dependencies on servers
-      - uses: actions/cache@v3
+      - uses: actions/cache@v4
         with:
           path: |
             .asdf/**