[fix][test] Fix multiple thread leaks in tests, part 2

[lhotari]

Motivation

There are thread leaks in tests reported by the thread leak detection added in #21450.

Modifications

Fix multiple thread leaks in unit tests.

Documentation

• doc
• doc-required
• doc-not-needed
• doc-complete

[codecov-commenter]

Codecov Report

Merging #21513 (a832e89) into master (99e6aeb) will decrease coverage by 0.03%.
Report is 1 commits behind head on master.
The diff coverage is 90.00%.

@@             Coverage Diff              @@
##             master   #21513      +/-   ##
============================================
- Coverage     73.22%   73.20%   -0.03%     
+ Complexity    32607    32604       -3     
============================================
  Files          1890     1890              
  Lines        140444   140451       +7     
  Branches      15436    15436              
============================================
- Hits         102839   102812      -27     
- Misses        29504    29542      +38     
+ Partials       8101     8097       -4     

Flag	Coverage Δ
inttests	24.12% <20.00%> (-0.09%)	⬇️
systests	24.71% <20.00%> (+0.01%)	⬆️
unittests	72.51% <90.00%> (-0.02%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
...a/org/apache/pulsar/proxy/server/ProxyService.java	78.84% <90.00%> (+0.19%)	⬆️

... and 78 files with indirect coverage changes