Move to use the included module for zoom dc

- we now are including the module, so
  we can remove this model specific definition

app/models/zoom_meeting.rb

@@ -25,10 +25,4 @@ class ZoomMeeting < ApplicationRecord
   def self.canonical_meeting_url(issue)
     canonical_meeting(issue)&.url
   end
-
-  def self.distinct_count_by(column = nil, fallback = -1)
-    distinct.count(column)
-  rescue ActiveRecord::StatementInvalid
-    fallback
-  end
 end

spec/models/zoom_meeting_spec.rb

@@ -151,51 +151,4 @@ describe ZoomMeeting do
       it_behaves_like 'can remove meetings'
     end
   end
-
-  describe '.distinct_count_by' do
-    let(:issue_1) { create(:issue) }
-    let(:issue_2) { create(:issue) }
-
-    context 'two meetings for the same issue' do
-      before do
-        create(:zoom_meeting, issue: issue_1)
-        create(:zoom_meeting, :removed_from_issue, issue: issue_1)
-      end
-
-      it 'returns a count of 1' do
-        expect(described_class.distinct_count_by(:issue_id)).to eq(1)
-      end
-
-      context 'when given no colum to count' do
-        it 'counts by :id and returns a count of 2' do
-          expect(described_class.distinct_count_by).to eq(2)
-        end
-      end
-    end
-
-    context 'one meeting for each issue' do
-      it 'returns a count of 2' do
-        create(:zoom_meeting, issue: issue_1)
-        create(:zoom_meeting, issue: issue_2)
-
-        expect(described_class.distinct_count_by(:issue_id)).to eq(2)
-      end
-    end
-
-    context 'the count query times out' do
-      before do
-        allow_next_instance_of(ActiveRecord::Relation) do |instance|
-          allow(instance).to receive(:count).and_raise(ActiveRecord::StatementInvalid.new(''))
-        end
-      end
-
-      it 'does not raise an error' do
-        expect { described_class.distinct_count_by(:issue_id) }.not_to raise_error
-      end
-
-      it 'returns -1' do
-        expect(described_class.distinct_count_by(:issue_id)).to eq(-1)
-      end
-    end
-  end
 end