chore(ci): update GitHub Actions to latest versions (#3573)

* Update nightly-ci.yml

* Update arbitrator-ci.yml

Author: Hopium21

.github/workflows/arbitrator-ci.yml

@@ -129,7 +129,7 @@ jobs:
 
       - name: Setup emsdk
         if: steps.cache-cbrotli.outputs.cache-hit != 'true'
-        uses: mymindstorm/setup-emsdk@v12
+        uses: mymindstorm/setup-emsdk@v14
         with:
           # Make sure to set a version number!
           version: 3.1.6

.github/workflows/nightly-ci.yml

@@ -344,7 +344,7 @@ jobs:
     if: ${{ failure() }}
     steps:
       - name: Send Slack notification
-        uses: slackapi/slack-github-action@v2.0.0
+        uses: slackapi/slack-github-action@v2.1.1
         with:
           errors: true
           method: chat.postMessage