Update GitHub Action action/checkout to v3

Author: taku0

.github/workflows/run-test.yml

@@ -23,7 +23,7 @@ jobs:
       ELDEV: .eldev/bin/eldev
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - uses: purcell/setup-emacs@master
       with:
         version: ${{ matrix.version }}