fix: last timeout in queueTrigger() never clears map

[gjanblaszczyk]

Description

EventTarget.queueTrigger() method contains a timeout code that should clear map when map.size === 0. However, It looks like
this statement will never trigger right now because the map has always size value bigger than 0.

Specific Changes proposed

The last timeout should delete the type from the map.

Requirements Checklist

• Feature implemented / Bug fixed
• If necessary, more likely in a feature request than a bug fix
  • Change has been verified in an actual browser (Chrome, Firefox, IE)
  • Unit Tests updated or fixed
  • Docs/guides updated
  • Example created (starter template on JSBin)
• Reviewed by Two Core Contributors

[codecov]

Codecov Report

Merging #7964 (31237ad) into main (ce1baba) will increase coverage by 0.03%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #7964      +/-   ##
==========================================
+ Coverage   80.94%   80.98%   +0.03%     
==========================================
  Files         116      116              
  Lines        7467     7472       +5     
  Branches     1816     1817       +1     
==========================================
+ Hits         6044     6051       +7     
+ Misses       1423     1421       -2     

Impacted Files	Coverage Δ
src/js/event-target.js	100.00% <100.00%> (+4.25%)	⬆️
src/js/extend.js	85.71% <100.00%> (+3.36%)	⬆️

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