Revert "DEV: Redo DiscourseLogstashLogger to not rely on logstash-logger (#27663)" (#27733)

This reverts commit 8e10878e1a37a608b0e1705bf9d0a06a295b8a63.

Something is broken on a friday so reverting first before I pick this up
again next Monday.

lib/discourse.rb

@@ -4,7 +4,6 @@ require "cache"
 require "open3"
 require "plugin/instance"
 require "version"
-require "git_utils"
 
 module Discourse
   DB_POST_MIGRATE_PATH ||= "db/post_migrate"
@@ -830,23 +829,42 @@ module Discourse
   end
 
   def self.git_version
-    @git_version ||= GitUtils.git_version
+    @git_version ||=
+      begin
+        git_cmd = "git rev-parse HEAD"
+        self.try_git(git_cmd, Discourse::VERSION::STRING)
+      end
   end
 
   def self.git_branch
-    @git_branch ||= GitUtils.git_branch
+    @git_branch ||=
+      self.try_git("git branch --show-current", nil) ||
+        self.try_git("git config user.discourse-version", "unknown")
   end
 
   def self.full_version
-    @full_version ||= GitUtils.full_version
+    @full_version ||=
+      begin
+        git_cmd = 'git describe --dirty --match "v[0-9]*" 2> /dev/null'
+        self.try_git(git_cmd, "unknown")
+      end
   end
 
   def self.last_commit_date
-    @last_commit_date ||= GitUtils.last_commit_date
+    @last_commit_date ||=
+      begin
+        git_cmd = 'git log -1 --format="%ct"'
+        seconds = self.try_git(git_cmd, nil)
+        seconds.nil? ? nil : DateTime.strptime(seconds, "%s")
+      end
   end
 
   def self.try_git(git_cmd, default_value)
-    GitUtils.try_git(git_cmd, default_value)
+    begin
+      `#{git_cmd}`.strip
+    rescue StandardError
+      default_value
+    end.presence || default_value
   end
 
   # Either returns the site_contact_username user or the first admin.