Remove already executed tasks

These tasks were executed when upgading to version 0.19, 1.0.0-beta or
1.0.0.

lib/tasks/budgets.rake

@@ -1,14 +1,4 @@
 namespace :budgets do
-  desc "Regenerate ballot_lines_count cache"
-  task calculate_ballot_lines: :environment do
-    ApplicationLogger.new.info "Calculating ballot lines"
-
-    Budget::Ballot.find_each.with_index do |ballot, index|
-      Budget::Ballot.reset_counters ballot.id, :lines
-      print "." if (index % 10_000).zero?
-    end
-  end
-
   namespace :email do
 
     desc "Sends emails to authors of selected investments"