Add HttpClientGitHubConnector and multirelease jar implementation

[bitwiseman]

Description

This change converts the production jar file to a multirelease jar file and adds a HttpClientGitHubConnector class to address reflection issues in Java 11+.

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[codecov]

Codecov Report

Merging #1300 (5699e58) into main (aad8b9a) will increase coverage by 0.02%.
The diff coverage is 80.00%.

@@             Coverage Diff              @@
##               main    #1300      +/-   ##
============================================
+ Coverage     77.86%   77.89%   +0.02%     
- Complexity     2011     2012       +1     
============================================
  Files           197      197              
  Lines          6220     6219       -1     
  Branches        362      359       -3     
============================================
+ Hits           4843     4844       +1     
- Misses         1160     1161       +1     
+ Partials        217      214       -3     

Impacted Files	Coverage Δ
...e/github/extras/okhttp3/OkHttpGitHubConnector.java	84.61% <ø> (-0.30%)	⬇️
...ohsuke/github/internal/DefaultGitHubConnector.java	92.30% <80.00%> (-7.70%)	⬇️
src/main/java/org/kohsuke/github/GHRepository.java	68.42% <0.00%> (ø)
...ava/org/kohsuke/github/GitHubRateLimitChecker.java	75.00% <0.00%> (+5.76%)	⬆️

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[nedtwigg]

Do you plan to cut a new release soon? Or are you planning to tackle every breaking change issue before shipping a new release?