Remove check for >9.6 for Geo

The general requirement is >= PG 11 today, so we should be able to
expect >9.6 anyways.

ee/app/controllers/admin/geo/nodes_controller.rb

@@ -8,10 +8,6 @@ class Admin::Geo::NodesController < Admin::Geo::ApplicationController
   def index
     @nodes = GeoNode.all.order(:id)
     @node = GeoNode.new
-
-    unless Gitlab::Database.postgresql_minimum_supported_version?
-      flash.now[:warning] = _('Please upgrade PostgreSQL to version 9.6 or greater. The status of the replication cannot be determined reliably with the current version.')
-    end
   end
   # rubocop: enable CodeReuse/ActiveRecord
 

ee/lib/gitlab/geo/geo_node_status_check.rb

@@ -19,7 +19,6 @@ def initialize(current_node_status, geo_node)
 
       def print_status
         print_current_node_info
-        print_postgres_version
 
         print_gitlab_version
         print_geo_role
@@ -151,16 +150,6 @@ def print_last_status_report_time
         end
       end
 
-      def print_postgres_version
-        unless Gitlab::Database.postgresql_minimum_supported_version?
-          puts
-          puts 'WARNING: Please upgrade PostgreSQL to version 9.6 or greater.'\
-            ' The status of the replication cannot be determined reliably '\
-            'with the current version.'.color(:red)
-          puts
-        end
-      end
-
       def print_repositories_status
         print 'Repositories: '.rjust(GEO_STATUS_COLUMN_WIDTH)
 

ee/spec/controllers/admin/geo/nodes_controller_spec.rb

@@ -65,22 +65,6 @@ def go
         expect(response).not_to redirect_to(:forbidden)
       end
     end
-
-    context 'with Postgres 9.6 or greater' do
-      before do
-        allow(Gitlab::Database).to receive(:postgresql_minimum_supported_version?).and_return(true)
-      end
-
-      it_behaves_like 'no flash message', :warning
-    end
-
-    context 'without Postgres 9.6 or greater' do
-      before do
-        allow(Gitlab::Database).to receive(:postgresql_minimum_supported_version?).and_return(false)
-      end
-
-      it_behaves_like 'with flash message', :warning, 'Please upgrade PostgreSQL to version 9.6 or greater.'
-    end
   end
 
   describe '#create' do

locale/gitlab.pot

@@ -16881,9 +16881,6 @@ msgstr ""
 msgid "Please type %{phrase_code} to proceed or close this modal to cancel."
 msgstr ""
-msgid "Please upgrade PostgreSQL to version 9.6 or greater. The status of the replication cannot be determined reliably with the current version."
-msgstr ""
-
 msgid "Please use this form to report to the admin users who create spam issues, comments or behave inappropriately."
 msgstr ""