Expire Wiki content cache after importing a repository

The cache state for Wikis that were imported via GitHub or Bitbucket does
not appear to have been flushed after a successful import.

Closes #47546

app/models/project.rb

@@ -1615,6 +1615,7 @@ class Project < ActiveRecord::Base
 
   def after_import
     repository.after_import
+    wiki.repository.after_import
     import_finish
     remove_import_jid
     update_project_counter_caches

changelogs/unreleased/sh-expire-content-cache-after-import.yml

@@ -0,0 +1,5 @@
+---
+title: Expire Wiki content cache after importing a repository
+merge_request:
+author:
+type: fixed

lib/gitlab/github_import/sequential_importer.rb

@@ -42,8 +42,6 @@ module Gitlab
           klass.new(project, client, parallel: false).execute
         end
 
-        project.repository.after_import
-
         true
       end
     end

lib/tasks/import.rake

@@ -50,7 +50,7 @@ class GithubImport
     end
 
     if import_success
-      @project.import_finish
+      @project.after_import
       puts "Import finished. Timings: #{timings}".color(:green)
     else
       puts "Import was not successful. Errors were as follows:"

spec/lib/gitlab/github_import/sequential_importer_spec.rb

@@ -30,7 +30,6 @@ describe Gitlab::GithubImport::SequentialImporter do
         expect(instance).to receive(:execute)
       end
 
-      expect(repository).to receive(:after_import)
       expect(importer.execute).to eq(true)
     end
   end

spec/models/project_spec.rb

@@ -3391,10 +3391,11 @@ describe Project do
   end
 
   describe '#after_import' do
-    let(:project) { build(:project) }
+    let(:project) { create(:project) }
 
     it 'runs the correct hooks' do
       expect(project.repository).to receive(:after_import)
+      expect(project.wiki.repository).to receive(:after_import)
       expect(project).to receive(:import_finish)
       expect(project).to receive(:update_project_counter_caches)
       expect(project).to receive(:remove_import_jid)