fix the read window update from the same thread

[TingDaoK]

Issue #, if available:

• We are adding the event back to the queue after we finish the task to delivery the current available events.
• When we add them back, it's possible that the window was open up for another delivery now.
• However, we only check for if new delivery needed or not when we open the window. And when the task is still running there is no outstanding deliveries, so we are NOT rescheduling the task and lead to a possible deadlock.
• So, we should check again when we add events back to the queue, but also check if there is available window as well to avoid infinite loop.
• It's okay to schedule another task while it's still running.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.19%. Comparing base (a109fa6) to head (2bfe376).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #601   +/-   ##
=======================================
  Coverage   89.18%   89.19%           
=======================================
  Files          23       23           
  Lines        7576     7579    +3     
=======================================
+ Hits         6757     6760    +3     
  Misses        819      819           

Files with missing lines	Coverage Δ
source/s3_meta_request.c	91.36% <100.00%> (+0.02%)	⬆️

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[DmitriyMusatkin]

Suggested change

	/* Push the iocompileted events back to the queue */
	/* Push the incomplete events back to the queue */