Remove identity context from output of LinkedDataSignature (#4753)

app/lib/activitypub/linked_data_signature.rb

@@ -45,7 +45,7 @@ class ActivityPub::LinkedDataSignature
 
     signature = Base64.strict_encode64(creator.keypair.sign(OpenSSL::Digest::SHA256.new, to_be_signed))
 
-    @json.merge('@context' => merge_context(@json['@context'], CONTEXT), 'signature' => options.merge('signatureValue' => signature))
+    @json.merge('signature' => options.merge('signatureValue' => signature))
   end
 
   private

spec/lib/activitypub/linked_data_signature_spec.rb

@@ -63,10 +63,6 @@ RSpec.describe ActivityPub::LinkedDataSignature do
       expect(subject).to be_a Hash
     end
 
-    it 'contains signature context' do
-      expect(subject['@context']).to include('https://www.w3.org/ns/activitystreams', 'https://w3id.org/identity/v1')
-    end
-
     it 'contains signature' do
       expect(subject['signature']).to be_a Hash
       expect(subject['signature']['signatureValue']).to be_present