refactor(queue): remove unnecessary index field in scheduledJob

[hongkuancn]

Hi!

I found the job queue is implemented according to example of container/heap - Go Packages. However, the index field is initialized in Item struct in the example (like the following code), while the scheduleJob struct doesn't do the same thing, so the index is always 0 in scheduleJob struct.

	for value, priority := range items {
		pq[i] = &Item{
			value:    value,
			priority: priority,
			index:    i,        //  <----  this line
		}
		i++
	}

Actually, I don't think the index is needed in scheduleJob. The index hasn't been used before because it hasn't been set up properly. So I just removed it.

Please let me know if there is anything I missed out.

[codecov-commenter]

⚠️ Please install the to ensure uploads and comments are reliably processed by Codecov.

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.62%. Comparing base (928d076) to head (2960968).
Report is 1 commits behind head on master.

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #136      +/-   ##
==========================================
- Coverage   94.95%   94.62%   -0.34%     
==========================================
  Files          19       19              
  Lines         972      967       -5     
==========================================
- Hits          923      915       -8     
- Misses         32       34       +2     
- Partials       17       18       +1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[reugn]

You're right, @hongkuancn. In the example, the index field is required by the update method, and is redundant in the quartz implementation.