Fix: var -> const. (#258)

Signed-off-by: dblock <[email protected]>

.github/workflows/coverage-comment.yml

@@ -26,7 +26,7 @@ jobs:
           github-token: ${{ secrets.GITHUB_TOKEN }}
           script: |
             const fs = require('fs');
-            var data = JSON.parse(fs.readFileSync('./coverage.json'));
+            const data = JSON.parse(fs.readFileSync('./coverage.json'));
             console.log(data);
             await github.issues.createComment({
               owner: context.repo.owner,