Fix typo in office hours assignment

Author: jun-hara

index.js

@@ -5,7 +5,7 @@ const unassignInactiveInHours = core.getInput('unassign_inactive_in_hours');
 const unassignInactiveMessage = core.getInput('unassign_inactive_message');
 const warningInactiveInHours = core.getInput('warning_inactive_in_hours');
 const warningInactiveMessage = core.getInput('warning_inactive_message');
-const officeHours = core.getInput('offce_hours');
+const officeHours = core.getInput('office_hours');
 const repoOwner = github.context.repo.owner;
 const repo = github.context.repo.repo;
 const octokit = github.getOctokit(token);