DEV: Use strings for :user_email job type argument

Job arguments go via JSON, and so symbols will appear as strings in the Job's `#execute` method. The latest version of Sidekiq has started warning about this to reduce developer confusion.

app/controllers/session_controller.rb

@@ -444,7 +444,7 @@ class SessionController < ApplicationController
     if user
       RateLimiter.new(nil, "forgot-password-login-day-#{user.username}", 6, 1.day).performed!
       email_token = user.email_tokens.create!(email: user.email, scope: EmailToken.scopes[:password_reset])
-      Jobs.enqueue(:critical_user_email, type: :forgot_password, user_id: user.id, email_token: email_token.token)
+      Jobs.enqueue(:critical_user_email, type: "forgot_password", user_id: user.id, email_token: email_token.token)
     else
       RateLimiter.new(nil, "forgot-password-login-hour-#{normalized_login_param}", 5, 1.hour).performed!
     end

app/controllers/users_controller.rb

@@ -737,7 +737,7 @@ class UsersController < ApplicationController
       session["user_created_message"] = activation.success_message
 
       if existing_user = User.find_by_email(user.primary_email&.email)
-        Jobs.enqueue(:critical_user_email, type: :account_exists, user_id: existing_user.id)
+        Jobs.enqueue(:critical_user_email, type: "account_exists", user_id: existing_user.id)
       end
 
       render json: {
@@ -932,7 +932,7 @@ class UsersController < ApplicationController
 
       if user = User.with_email(params[:email]).admins.human_users.first
         email_token = user.email_tokens.create!(email: user.email, scope: EmailToken.scopes[:email_login])
-        Jobs.enqueue(:critical_user_email, type: :admin_login, user_id: user.id, email_token: email_token.token)
+        Jobs.enqueue(:critical_user_email, type: "admin_login", user_id: user.id, email_token: email_token.token)
         @message = I18n.t("admin_login.success")
       else
         @message = I18n.t("admin_login.errors.unknown_email_address")
@@ -967,7 +967,7 @@ class UsersController < ApplicationController
         email_token = user.email_tokens.create!(email: user.email, scope: EmailToken.scopes[:email_login])
 
         Jobs.enqueue(:critical_user_email,
-          type: :email_login,
+          type: "email_login",
           user_id: user.id,
           email_token: email_token.token
         )

app/jobs/regular/suspicious_login.rb

@@ -13,7 +13,7 @@ module Jobs
                           client_ip: args[:client_ip])
 
         ::Jobs.enqueue(:critical_user_email,
-                     type: :suspicious_login,
+                     type: "suspicious_login",
                      user_id: args[:user_id],
                      client_ip: args[:client_ip],
                      user_agent: args[:user_agent])

app/jobs/scheduled/enqueue_digest_emails.rb

@@ -10,7 +10,7 @@ module Jobs
       users = target_user_ids
 
       users.each do |user_id|
-        ::Jobs.enqueue(:user_email, type: :digest, user_id: user_id)
+        ::Jobs.enqueue(:user_email, type: "digest", user_id: user_id)
       end
     end
 

lib/email_updater.rb

@@ -24,7 +24,7 @@ class EmailUpdater
 
     if existing_user = User.find_by_email(email)
       if SiteSetting.hide_email_address_taken
-        Jobs.enqueue(:critical_user_email, type: :account_exists, user_id: existing_user.id)
+        Jobs.enqueue(:critical_user_email, type: "account_exists", user_id: existing_user.id)
       else
         error_message = +'change_email.error'
         error_message << '_staged' if existing_user.staged?

lib/tasks/admin.rake

@@ -28,7 +28,7 @@ task "admin:invite", [:email] => [:environment] do |_, args|
 
   puts "Sending email!"
   email_token = user.email_tokens.create!(email: user.email, scope: EmailToken.scopes[:password_reset])
-  Jobs.enqueue(:user_email, type: :account_created, user_id: user.id, email_token: email_token.token)
+  Jobs.enqueue(:user_email, type: "account_created", user_id: user.id, email_token: email_token.token)
 end
 
 desc "Creates a forum administrator"