Fix: unregister UncaughtExceptionHandler on close.

[maciejwalkowiak]

📜 Description

Fix: unregister UncaughtExceptionHandler on close.

💡 Motivation and Context

Fixes #1767

💚 How did you test it?

📝 Checklist

• I reviewed the submitted code
• I added tests to verify the changes
• I updated the docs if needed
• No breaking changes

[codecov-commenter]

Codecov Report

Merging #1770 (7386858) into main (b2eb278) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##               main    #1770   +/-   ##
=========================================
  Coverage     75.31%   75.32%           
  Complexity     2165     2165           
=========================================
  Files           215      215           
  Lines          7718     7717    -1     
  Branches        822      821    -1     
=========================================
  Hits           5813     5813           
  Misses         1507     1507           
+ Partials        398      397    -1     

Impacted Files	Coverage Δ
.../main/java/io/sentry/UncaughtExceptionHandler.java	100.00% <ø> (ø)
...io/sentry/UncaughtExceptionHandlerIntegration.java	76.00% <100.00%> (+1.00%)	⬆️

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