Remove the connect feature flag (#17061)

There's an existing data update to introduce the connect feature flag,
and it's been disabled. However, since all the code relying on this is
now gone, it makes sense to remove the flag.

lib/data_update_scripts/20220330191441_remove_connect_feature_flag.rb

@@ -0,0 +1,7 @@
+module DataUpdateScripts
+  class RemoveConnectFeatureFlag
+    def run
+      FeatureFlag.remove(:connect)
+    end
+  end
+end

spec/lib/data_update_scripts/remove_connect_feature_flag_spec.rb

@@ -0,0 +1,14 @@
+require "rails_helper"
+require Rails.root.join(
+  "lib/data_update_scripts/20220330191441_remove_connect_feature_flag.rb",
+)
+
+describe DataUpdateScripts::RemoveConnectFeatureFlag do
+  it "removes the connect feature flag" do
+    FeatureFlag.add(:connect)
+
+    described_class.new.run
+
+    expect(FeatureFlag.exist?(:connect)).to be false
+  end
+end