FIX: Approves user when redeeming an invite for invites only sites (#16984)

When a site has `SiteSetting.invite_only` enabled, we create a
`ReviewableUser`record when activating a user if the user is not
approved. Therefore, we need to approve the user when redeeming an
invite.

There are some uncertainties surrounding why a `ReviewableRecord` is
created for a user in an invites only site but this commit does not seek
to address that.

Follow-up to 7c4e2d33fa

spec/models/invite_redeemer_spec.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 describe InviteRedeemer do
+  fab!(:admin) { Fabricate(:admin) }
 
   describe '.create_user_from_invite' do
     it "should be created correctly" do
@@ -83,6 +84,32 @@ describe InviteRedeemer do
       expect(user.approved).to eq(false)
       expect(user.active).to eq(false)
     end
+
+    it "approves and actives user when redeeming an invite with email token and SiteSetting.invite_only is enabled" do
+      SiteSetting.invite_only = true
+      Jobs.run_immediately!
+
+      invite = Fabricate(:invite,
+        invited_by: admin,
+        email: 'walter.white@email.com',
+        emailed_status: Invite.emailed_status_types[:sent],
+      )
+
+      user = InviteRedeemer.create_user_from_invite(
+        invite: invite,
+        email: invite.email,
+        email_token: invite.email_token,
+        username: 'walter',
+        name: 'Walter White'
+      )
+
+      expect(user.name).to eq("Walter White")
+      expect(user.username).to eq("walter")
+      expect(user.email).to eq("walter.white@email.com")
+      expect(user.approved).to eq(true)
+      expect(user.active).to eq(true)
+      expect(ReviewableUser.count).to eq(0)
+    end
   end
 
   describe "#redeem" do