Update actions/checkout action to v3

Generated by renovateBot

Author: renovate-bot

.github/workflows/browser-e2e.yaml

@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
       - name: test
         run: |
           docker build -t pion-webrtc-e2e -f e2e/Dockerfile .

.github/workflows/standardjs.yaml

@@ -9,7 +9,7 @@ jobs:
   StandardJS:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: actions/setup-node@v2
         with:
           node-version: 12.x