ci(pr-metadata): stop assigning the suspended TechEngineBot

Assigning a suspended account makes the whole assignees call 404 on every
PR regardless of which token calls it. Assign the PR author only until the
bot account is reinstated.

Refs #350

Author: Seungpyo1007

.github/workflows/pr-metadata.yml

@@ -27,7 +27,10 @@ jobs:
             const repo = context.repo.repo;
             const issue_number = pr.number;
 
-            const assignees = ['TechEngineBot'];
+            // TechEngineBot is left out while its GitHub account is suspended:
+            // assigning a suspended user 404s the whole call regardless of token.
+            // Re-add it here once the account is reinstated.
+            const assignees = [];
             if (!pr.user?.type?.endsWith('Bot')) {
               assignees.push(pr.user.login);
             }