[rubygems/rubygems] Support git 2.49

One error message that we parse is now slightly different.

758528791d

lib/bundler/source/git/git_proxy.rb

@@ -179,7 +179,8 @@ module Bundler
             _, err, status = capture(command, nil)
             return extra_ref if status.success?
 
-            if err.include?("Could not find remote branch")
+            if err.include?("Could not find remote branch") || # git up to 2.49
+               err.include?("Remote branch #{branch_option} not found") # git 2.49 or higher
               raise MissingGitRevisionError.new(command_with_no_credentials, nil, explicit_ref, credential_filtered_uri)
             else
               idx = command.index("--depth")
@@ -256,7 +257,7 @@ module Bundler
         end
 
         def not_pinned?
-          branch || tag || ref.nil?
+          branch_option || ref.nil?
         end
 
         def pinned_to_full_sha?
@@ -420,7 +421,7 @@ module Bundler
           # anyways.
           return args if @revision
 
-          args += ["--branch", branch || tag] if branch || tag
+          args += ["--branch", branch_option] if branch_option
           args
         end
 
@@ -436,6 +437,10 @@ module Bundler
           extra_args
         end
 
+        def branch_option
+          branch || tag
+        end
+
         def full_clone?
           depth.nil?
         end