Update github actions versions due to deprecation (ethereum#392)

Author: PixelPil0t1

.github/workflows/deploy.yaml

@@ -14,7 +14,7 @@ jobs:
         working-directory: ./jsonrpc
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: Use Node.js 15
         uses: actions/setup-node@v2
         with:

.github/workflows/test.yaml

@@ -15,7 +15,7 @@ jobs:
         node-version: [16.x]
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: Use Node.js ${{ matrix.node-version }}
         uses: actions/setup-node@v2
         with: