Bump version of GHA

Author: josherrickson

.github/workflows/r.yml

@@ -31,7 +31,7 @@ jobs:
       R_REMOTES_NO_ERRORS_FROM_WARNINGS: true
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - uses: r-lib/actions/setup-pandoc@v2