Re-enable the tests skipped on FreeBSD for [Bug #18613]

The signal handling bug behind these was fixed in FreeBSD 13.3, and 13 is
now EOL. Each of them ran 30 times, and the affected files together 20
times, on the rubyci FreeBSD 14.5 amd64 and 15.1 arm64 machines with no
failure.

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=277429

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

test/.excludes/TestThread.rb

@@ -1,17 +1,5 @@
 # frozen_string_literal: false
 exclude(/_stack_size$/, 'often too expensive')
-if /freebsd13/ =~ RUBY_PLATFORM
-  # http://rubyci.s3.amazonaws.com/freebsd13/ruby-master/log/20220216T143001Z.fail.html.gz
-  #
-  #   1) Error:
-  # TestThread#test_signal_at_join:
-  # Timeout::Error: execution of assert_separately expired timeout (120 sec)
-  # pid 30743 killed by SIGABRT (signal 6) (core dumped)
-  # |
-  #
-  #     /usr/home/chkbuild/chkbuild/tmp/build/20220216T143001Z/ruby/test/ruby/test_thread.rb:1390:in `test_signal_at_join'
-  exclude(:test_signal_at_join, 'gets stuck somewhere')
-end
 if /mswin/ =~ RUBY_PLATFORM && ENV.key?('GITHUB_ACTIONS')
   # to avoid "`failed to allocate memory (NoMemoryError)" error
   exclude(:test_thread_interrupt_for_killed_thread, 'TODO')

test/.excludes/TestThreadQueue.rb

@@ -1,9 +0,0 @@
-# frozen_string_literal: false
-if /freebsd13/ =~ RUBY_PLATFORM
-  # http://rubyci.s3.amazonaws.com/freebsd13/ruby-master/log/20220308T023001Z.fail.html.gz
-  #
-  #   1) Failure:
-  # TestThreadQueue#test_thr_kill [/usr/home/chkbuild/chkbuild/tmp/build/20220308T023001Z/ruby/test/ruby/test_thread_queue.rb:175]:
-  # only 169/250 done in 60 seconds.
-  exclude(:test_thr_kill, 'gets stuck somewhere')
-end

test/ruby/test_file_exhaustive.rb

@@ -1466,8 +1466,6 @@ class TestFileExhaustive < Test::Unit::TestCase
   end
 
   def test_flock_exclusive
-    omit "[Bug #18613]" if /freebsd/ =~ RUBY_PLATFORM
-
     timeout = EnvUtil.apply_timeout_scale(1).to_s
     File.open(regular_file, "r+") do |f|
       f.flock(File::LOCK_EX)
@@ -1497,8 +1495,6 @@ class TestFileExhaustive < Test::Unit::TestCase
   end
 
   def test_flock_shared
-    omit "[Bug #18613]" if /freebsd/ =~ RUBY_PLATFORM
-
     timeout = EnvUtil.apply_timeout_scale(1).to_s
     File.open(regular_file, "r+") do |f|
       f.flock(File::LOCK_SH)

test/ruby/test_io.rb

@@ -3606,8 +3606,6 @@ __END__
   end
 
   def test_cross_thread_close_stdio
-    omit "[Bug #18613]" if /freebsd/ =~ RUBY_PLATFORM
-
     assert_separately([], <<-'end;')
       IO.pipe do |r,w|
         $stdin.reopen(r)
@@ -4302,8 +4300,6 @@ __END__
   end
 
   def test_race_closed_stream
-    omit "[Bug #18613]" if /freebsd/ =~ RUBY_PLATFORM
-
     assert_separately([], "#{<<-"begin;"}\n#{<<-"end;"}")
     begin;
       bug13158 = '[ruby-core:79262] [Bug #13158]'
@@ -4398,8 +4394,6 @@ __END__
     end
 
     def test_closed_stream_in_rescue
-      omit "[Bug #18613]" if /freebsd/ =~ RUBY_PLATFORM
-
       assert_separately([], "#{<<-"begin;"}\n#{<<~"end;"}")
       begin;
       10.times do

test/ruby/test_require.rb

@@ -889,8 +889,6 @@ class TestRequire < Test::Unit::TestCase
   end if File.respond_to?(:mkfifo)
 
   def test_loading_fifo_threading_success
-    omit "[Bug #18613]" if /freebsd/=~ RUBY_PLATFORM
-
     Tempfile.create(%w'fifo .rb') {|f|
       f.close
       File.unlink(f.path)

test/ruby/test_thread.rb

@@ -1009,8 +1009,6 @@ _eom
   end
 
   def test_thread_timer_and_interrupt
-    omit "[Bug #18613]" if /freebsd/ =~ RUBY_PLATFORM
-
     bug5757 = '[ruby-dev:44985]'
     pid = nil
     cmd = 'Signal.trap(:INT, "DEFAULT"); pipe=IO.pipe; Thread.start {Thread.pass until Thread.main.stop?; puts; STDOUT.flush}; pipe[0].read'
@@ -1530,10 +1528,6 @@ q.pop
       # opt = {new_pgroup: true}
     end
 
-    if /freebsd/ =~ RUBY_PLATFORM
-      omit "[Bug #18613]"
-    end
-
     assert_separately([], "#{<<~"{#"}\n#{<<~'};'}", timeout: 120)
     {#
       n = 1000

test/ruby/test_thread_queue.rb

@@ -213,8 +213,6 @@ class TestThreadQueue < Test::Unit::TestCase
   end
 
   def test_thr_kill
-    omit "[Bug #18613]" if /freebsd/ =~ RUBY_PLATFORM
-
     bug5343 = '[ruby-core:39634]'
     Dir.mktmpdir {|d|
       timeout = 120

test/socket/test_socket.rb

@@ -574,7 +574,7 @@ class TestSocket < Test::Unit::TestCase
   ensure
     serv_thread.value.close
     server.close
-  end unless RUBY_PLATFORM.include?("freebsd")
+  end
 
   def test_connect_timeout
     host = "127.0.0.1"