Remove snippets#show JSON format handling

The JSON format handling for snippets#show endpoint does
not appear to be in use since moving to Vue, this commit
removes it to clean up the controllers

app/controllers/concerns/snippets_actions.rb

@@ -57,11 +57,6 @@ module SnippetsActions
         render 'show'
       end
 
-      format.json do
-        conditionally_expand_blob(blob)
-        render_blob_json(blob)
-      end
-
       format.js do
         if @snippet.embeddable?
           conditionally_expand_blobs(blobs)

spec/controllers/projects/snippets_controller_spec.rb

@@ -180,16 +180,6 @@ RSpec.describe Projects::SnippetsController do
     end
   end
 
-  describe 'GET #show as JSON' do
-    it 'renders the blob from the repository' do
-      project_snippet = create(:project_snippet, :public, :repository, project: project, author: user)
-
-      get :show, params: { namespace_id: project.namespace, project_id: project, id: project_snippet.to_param }, format: :json
-
-      expect(assigns(:blob)).to eq(project_snippet.blobs.first)
-    end
-  end
-
   describe "GET #show for embeddable content" do
     let(:project_snippet) { create(:project_snippet, :repository, snippet_permission, project: project, author: user) }
     let(:extra_params) { {} }

spec/controllers/snippets_controller_spec.rb

@@ -205,14 +205,6 @@ RSpec.describe SnippetsController do
         end
       end
     end
-
-    context 'when requesting JSON' do
-      it 'renders the blob from the repository' do
-        get :show, params: { id: public_snippet.to_param }, format: :json
-
-        expect(assigns(:blob)).to eq(public_snippet.blobs.first)
-      end
-    end
   end
 
   describe 'POST #mark_as_spam' do