Remove unused method

It was used to determine if rake is running,
now we use other method

ee/lib/gitlab/database/load_balancing.rb

@@ -121,10 +121,6 @@ module Gitlab
                              ::License.feature_available?(:db_load_balancing)
       end
 
-      def self.program_name
-        @program_name ||= File.basename($0)
-      end
-
       def self.start_service_discovery
         return unless service_discovery_enabled?
 

ee/spec/lib/gitlab/database/load_balancing_spec.rb

@@ -209,7 +209,6 @@ RSpec.describe Gitlab::Database::LoadBalancing do
     it 'returns true when Sidekiq is being used' do
       allow(described_class).to receive(:hosts).and_return(%w(foo))
       allow(Gitlab::Runtime).to receive(:sidekiq?).and_return(true)
-      expect(described_class).not_to receive(:program_name)
 
       expect(described_class.configured?).to eq(true)
     end
@@ -246,12 +245,6 @@ RSpec.describe Gitlab::Database::LoadBalancing do
     end
   end
 
-  describe '.program_name' do
-    it 'returns a String' do
-      expect(described_class.program_name).to be_an_instance_of(String)
-    end
-  end
-
   describe '.configure_proxy' do
     after do
       described_class.clear_configuration