File really-skip-the-sendmail-tests.patch of Package ruby4.0

commit 3d8dfbf51e0133e76e5dca4f408c8f7efb6698b3
Author: Hiroshi SHIBATA <hsbt@ruby-lang.org>
Date:   Mon Nov 17 16:07:46 2025 +0900

    Skip TestCommitEmail if git is not available.
    
    https://github.com/ruby/actions/actions/runs/19420968008/job/55558315338
    
    ```
        1) Error:
      TestCommitEmail#test_sendmail_encoding:
      Test::Unit::ProxyError: No such file or directory - git
          /home/runner/work/actions/actions/ruby-4.0.0-preview2/lib/open3.rb:534:in 'Kernel#spawn'
          /home/runner/work/actions/actions/ruby-4.0.0-preview2/lib/open3.rb:534:in 'Open3.popen_run'
          /home/runner/work/actions/actions/ruby-4.0.0-preview2/lib/open3.rb:379:in 'Open3.popen2'
          /home/runner/work/actions/actions/ruby-4.0.0-preview2/lib/open3.rb:785:in 'Open3.capture2'
          /home/runner/work/actions/actions/ruby-4.0.0-preview2/tool/test/test_commit_email.rb:89:in 'TestCommitEmail#git'
          /home/runner/work/actions/actions/ruby-4.0.0-preview2/tool/test/test_commit_email.rb:13:in 'block in TestCommitEmail#setup'
          /home/runner/work/actions/actions/ruby-4.0.0-preview2/tool/test/test_commit_email.rb:12:in 'Dir.chdir'
          /home/runner/work/actions/actions/ruby-4.0.0-preview2/tool/test/test_commit_email.rb:12:in 'TestCommitEmail#setup'
    
        2) Error:
      TestCommitEmail#test_sendmail_encoding:
      Test::Unit::ProxyError: no implicit conversion of nil into String
          /home/runner/work/actions/actions/ruby-4.0.0-preview2/tool/test/test_commit_email.rb:37:in 'File.unlink'
          /home/runner/work/actions/actions/ruby-4.0.0-preview2/tool/test/test_commit_email.rb:37:in 'TestCommitEmail#teardown'
    ```

Index: ruby-4.0.0-preview2/tool/test/test_commit_email.rb
===================================================================
--- ruby-4.0.0-preview2.orig/tool/test/test_commit_email.rb
+++ ruby-4.0.0-preview2/tool/test/test_commit_email.rb
@@ -36,6 +36,7 @@ class TestCommitEmail < Test::Unit::Test
   end
 
   def teardown
+    omit 'git command is not available' unless system('git', '--version', out: File::NULL, err: File::NULL)
     File.unlink(@sendmail)
     Dir.rmdir(File.dirname(@sendmail))
     FileUtils.rm_rf(@ruby)
@@ -43,6 +44,7 @@ class TestCommitEmail < Test::Unit::Test
 
   def test_sendmail_encoding
     omit 'the sendmail script does not work on windows' if windows?
+    omit 'git command is not available' unless system('git', '--version', out: File::NULL, err: File::NULL)
 
     Dir.chdir(@ruby) do
       before_rev = git('rev-parse', 'HEAD^').chomp