v1.15.2

[ashie]

Which issue(s) this PR fixes:
None

What this PR does / why we need it:

Docs Changes:
None

Release Note:
None

[fujimotos]

FWIW, I'm experimenting with the latest master so that we can be sure
that v4.4.1 works flawlessly.

I'm planning to test both on RHEL and Windows, since I observe #3866
affects fluentwinsvc. So wait for me.

[ashie]

BTW today we always get following error with ruby 3.2.0dev (2022-08-22 master 9f3140a42e) [x64-mingw-ucrt] on Windows:
https://github.com/fluent/fluentd/runs/7945647354?check_suite_focus=true

2022-08-22T06:26:48.0261596Z   keepalive: 
2022-08-22T06:26:48.7718954Z     test: Do not create connection per send_data:	.: (0.745608)
2022-08-22T06:26:49.0457212Z     test: create timer of purging obsolete sockets:	.: (0.273691)
2022-08-22T06:26:49.0458376Z     with require_ack_response: 
2022-08-22T06:26:49.8032564Z #<Thread:0x000001febc53fe78@event_loop D:/a/fluentd/fluentd/lib/fluent/plugin_helper/thread.rb:70 run> terminated with exception (report_on_exception is true):
2022-08-22T06:26:49.8044023Z D:/rubyinstaller-head-x64/lib/ruby/gems/3.2.0+2/gems/cool.io-1.7.1/lib/cool.io/io.rb:35:in `attach': expected loop to be an instance of Coolio::Loop, not nil (ArgumentError)
2022-08-22T06:26:49.8044554Z 
2022-08-22T06:26:49.8044905Z       @_read_watcher.attach(loop)
2022-08-22T06:26:49.8045358Z                             ^^^^
2022-08-22T06:26:49.8047633Z 	from D:/rubyinstaller-head-x64/lib/ruby/gems/3.2.0+2/gems/cool.io-1.7.1/lib/cool.io/io.rb:35:in `attach'
2022-08-22T06:26:49.8052740Z 	from D:/rubyinstaller-head-x64/lib/ruby/gems/3.2.0+2/gems/cool.io-1.7.1/lib/cool.io/socket.rb:39:in `attach'
2022-08-22T06:26:49.8053208Z 	from (eval):7:in `attach'
2022-08-22T06:26:49.8053789Z 	from D:/rubyinstaller-head-x64/lib/ruby/gems/3.2.0+2/gems/cool.io-1.7.1/lib/cool.io/server.rb:40:in `on_connection'
2022-08-22T06:26:49.8054504Z 	from D:/rubyinstaller-head-x64/lib/ruby/gems/3.2.0+2/gems/cool.io-1.7.1/lib/cool.io/listener.rb:65:in `on_readable'
2022-08-22T06:26:49.8055191Z 	from D:/rubyinstaller-head-x64/lib/ruby/gems/3.2.0+2/gems/cool.io-1.7.1/lib/cool.io/loop.rb:88:in `run_once'
2022-08-22T06:26:49.8055848Z 	from D:/rubyinstaller-head-x64/lib/ruby/gems/3.2.0+2/gems/cool.io-1.7.1/lib/cool.io/loop.rb:88:in `run'
2022-08-22T06:26:49.8056338Z 	from D:/a/fluentd/fluentd/lib/fluent/plugin_helper/event_loop.rb:93:in `block in start'
2022-08-22T06:26:49.8056825Z 	from D:/a/fluentd/fluentd/lib/fluent/plugin_helper/thread.rb:78:in `block in thread_create'
2022-08-22T06:26:50.2666186Z       test: Create connection per send_data:		E
2022-08-22T06:26:50.2666978Z ===============================================================================
2022-08-22T06:26:50.2670563Z Error: test: Create connection per send_data(ForwardOutputTest::keepalive::with require_ack_response): ArgumentError: expected loop to be an instance of Coolio::Loop, not nil
2022-08-22T06:26:50.2672222Z D:/rubyinstaller-head-x64/lib/ruby/gems/3.2.0+2/gems/cool.io-1.7.1/lib/cool.io/io.rb:35:in `attach'
2022-08-22T06:26:50.2673551Z D:/rubyinstaller-head-x64/lib/ruby/gems/3.2.0+2/gems/cool.io-1.7.1/lib/cool.io/io.rb:35:in `attach'
2022-08-22T06:26:50.2675050Z D:/rubyinstaller-head-x64/lib/ruby/gems/3.2.0+2/gems/cool.io-1.7.1/lib/cool.io/socket.rb:39:in `attach'
2022-08-22T06:26:50.2675808Z (eval):7:in `attach'
2022-08-22T06:26:50.2676773Z D:/rubyinstaller-head-x64/lib/ruby/gems/3.2.0+2/gems/cool.io-1.7.1/lib/cool.io/server.rb:40:in `on_connection'
2022-08-22T06:26:50.2677918Z D:/rubyinstaller-head-x64/lib/ruby/gems/3.2.0+2/gems/cool.io-1.7.1/lib/cool.io/listener.rb:65:in `on_readable'
2022-08-22T06:26:50.2679011Z D:/rubyinstaller-head-x64/lib/ruby/gems/3.2.0+2/gems/cool.io-1.7.1/lib/cool.io/loop.rb:88:in `run_once'
2022-08-22T06:26:50.2680245Z D:/rubyinstaller-head-x64/lib/ruby/gems/3.2.0+2/gems/cool.io-1.7.1/lib/cool.io/loop.rb:88:in `run'
2022-08-22T06:26:50.2681169Z D:/a/fluentd/fluentd/lib/fluent/plugin_helper/event_loop.rb:93:in `block in start'
2022-08-22T06:26:50.2682012Z D:/a/fluentd/fluentd/lib/fluent/plugin_helper/thread.rb:78:in `block in thread_create'

3 days ago we succeeded to run tests with ruby 3.2 on Windows though:
https://github.com/fluent/fluentd/runs/7913475855?check_suite_focus=true
ruby 3.2.0dev (2022-08-19 master 35c794b26d) [x64-mingw-ucrt]

Changes in Ruby: https://github.com/ruby/ruby/compare/35c794b..9f3140a

[fujimotos]

OK. I built a Windows MSI installer and a RPM package based on a2807c6,
and tested them on Windows Server 2019 and RHEL 8.6.

I can confirm these packages work. Here is some screenshots: