Deprecate diverging commit count with max parameter

In 12.0, we turned the feature flag on that effectively turned off the
--max-count flag for the count diverging commits call. Since we have
commit graphs turned on, this did not affect preformance negatively.
Thus, we want to deprecate the call that passes --max-count

app/helpers/branches_helper.rb

@@ -8,12 +8,4 @@ module BranchesHelper
   def protected_branch?(project, branch)
     ProtectedBranch.protected?(project, branch.name)
   end
-
-  def diverging_count_label(count)
-    if count >= Repository::MAX_DIVERGING_COUNT
-      "#{Repository::MAX_DIVERGING_COUNT - 1}+"
-    else
-      count.to_s
-    end
-  end
 end

app/models/repository.rb

@@ -6,7 +6,6 @@ class Repository
   REF_MERGE_REQUEST = 'merge-requests'.freeze
   REF_KEEP_AROUND = 'keep-around'.freeze
   REF_ENVIRONMENTS = 'environments'.freeze
-  MAX_DIVERGING_COUNT = 1000
 
   RESERVED_REFS_NAMES = %W[
     heads

app/services/branches/diverging_commit_counts_service.rb

@@ -8,12 +8,8 @@ module Branches
     end
 
     def call(branch)
-      if Feature.enabled?('gitaly_count_diverging_commits_no_max')
-        diverging_commit_counts_without_max(branch)
-      else
       diverging_commit_counts(branch)
     end
-    end
 
     private
 
@@ -22,26 +18,8 @@ module Branches
     delegate :raw_repository, to: :repository
 
     def diverging_commit_counts(branch)
-      ## TODO: deprecate the below code after 12.0
       @root_ref_hash ||= raw_repository.commit(repository.root_ref).id
       cache.fetch(:"diverging_commit_counts_#{branch.name}") do
-        number_commits_behind, number_commits_ahead =
-          repository.raw_repository.diverging_commit_count(
-            @root_ref_hash,
-            branch.dereferenced_target.sha,
-            max_count: Repository::MAX_DIVERGING_COUNT)
-
-        if number_commits_behind + number_commits_ahead >= Repository::MAX_DIVERGING_COUNT
-          { distance: Repository::MAX_DIVERGING_COUNT }
-        else
-          { behind: number_commits_behind, ahead: number_commits_ahead }
-        end
-      end
-    end
-
-    def diverging_commit_counts_without_max(branch)
-      @root_ref_hash ||= raw_repository.commit(repository.root_ref).id
-      cache.fetch(:"diverging_commit_counts_without_max_#{branch.name}") do
         number_commits_behind, number_commits_ahead =
           raw_repository.diverging_commit_count(
             @root_ref_hash,

spec/services/branches/diverging_commit_counts_service_spec.rb

@@ -19,11 +19,6 @@ describe Branches::DivergingCommitCountsService do
       expect(result).to eq(behind: 29, ahead: 2)
     end
 
-    context 'when gitaly_count_diverging_commits_no_max is enabled' do
-      before do
-        stub_feature_flags(gitaly_count_diverging_commits_no_max: true)
-      end
-
     it 'calls diverging_commit_count without max count' do
       expect(repository.raw_repository)
         .to receive(:diverging_commit_count)
@@ -33,20 +28,4 @@ describe Branches::DivergingCommitCountsService do
       service.call(diverged_branch)
     end
   end
-
-    context 'when gitaly_count_diverging_commits_no_max is disabled' do
-      before do
-        stub_feature_flags(gitaly_count_diverging_commits_no_max: false)
-      end
-
-      it 'calls diverging_commit_count with max count' do
-        expect(repository.raw_repository)
-          .to receive(:diverging_commit_count)
-          .with(root_ref_sha, diverged_branch_sha, max_count: Repository::MAX_DIVERGING_COUNT)
-          .and_return([29, 2])
-
-        service.call(diverged_branch)
-      end
-    end
-  end
 end