Pull in net-smtp manually

We need to do this as the `mail` gem hasn't yet been updated. See mikel/mail#1439.

Gemfile

@@ -83,6 +83,9 @@ gem 'validates_timeliness', '>= 5.0.0.beta1'
 
 gem "get_into_teaching_api_client_faraday", github: "DFE-Digital/get-into-teaching-api-ruby-client", require: "api/client"
 
+# See https://github.com/mikel/mail/pull/1439
+gem 'net-smtp', require: false 
+
 # Ignore cloudfront IPs when getting customer IP address
 gem 'actionpack-cloudfront', '>= 1.2.0'
 

Gemfile.lock

@@ -203,6 +203,7 @@ GEM
       rack-protection (>= 1.5.5)
       sinatra (>= 1.4.4)
     diff-lcs (1.5.0)
+    digest (3.1.0)
     docile (1.4.0)
     dotenv (2.7.6)
     dotenv-rails (2.7.6)
@@ -270,6 +271,7 @@ GEM
     ice_cube (0.16.4)
     invisible_captcha (2.0.0)
       rails (>= 5.0)
+    io-wait (0.2.1)
     json (2.6.1)
     json-jwt (1.13.0)
       activesupport (>= 4.2)
@@ -314,6 +316,13 @@ GEM
     multipart-post (2.1.1)
     mustermann (1.1.1)
       ruby2_keywords (~> 0.0.1)
+    net-protocol (0.1.2)
+      io-wait
+      timeout
+    net-smtp (0.3.1)
+      digest
+      net-protocol
+      timeout
     nio4r (2.5.8)
     nokogiri (1.13.3)
       mini_portile2 (~> 2.8.0)
@@ -546,6 +555,7 @@ GEM
     thor (1.2.1)
     tilt (2.0.10)
     timeliness (0.4.4)
+    timeout (0.2.0)
     tzinfo (2.0.4)
       concurrent-ruby (~> 1.0)
     uk_postcode (2.1.7)
@@ -640,6 +650,7 @@ DEPENDENCIES
   kaminari
   listen (>= 3.0.5)
   meta-tags (~> 2.16, >= 2.16.0)
+  net-smtp
   notifications-ruby-client
   openid_connect
   parallel_tests
@@ -686,7 +697,7 @@ DEPENDENCIES
   yabeda-rails
 
 RUBY VERSION
-   ruby 2.7.5p203
+   ruby 3.1.0p0
 
 BUNDLED WITH
    2.3.4