[Credo] Remove parentesis on argument-less functions

lib/pleroma/application.ex

lib/pleroma/captcha/captcha.ex

lib/pleroma/captcha/kocaptcha.ex

lib/pleroma/clippy.ex

lib/pleroma/config/deprecation_warnings.ex

lib/pleroma/emoji.ex

lib/pleroma/flake_id.ex

lib/pleroma/gopher/server.ex

lib/pleroma/html.ex

lib/pleroma/uploaders/swift/keystone.ex

lib/pleroma/user.ex

lib/pleroma/user/welcome_message.ex

lib/pleroma/web/activity_pub/mrf.ex

lib/pleroma/web/chat_channel.ex

lib/pleroma/web/federator/federator.ex

lib/pleroma/web/federator/retry_queue.ex

lib/pleroma/web/mastodon_api/mastodon_api_controller.ex

lib/pleroma/web/push/push.ex

test/support/captcha_mock.ex