Add mail protocol gems

This is required for ruby 3.1 with rails 6.1, as they were removed from
being bundled with ruby 3.1. It can be removed with rails 7 again, as
they were added as a dependency to rails 7.

Gemfile

@@ -4,6 +4,11 @@ source "https://rubygems.org"
 
 gem "rails", "6.1.6.1"
 
+# needed for actionmailer, can be removed when upgrading to rails 7
+gem "net-imap", require: false
+gem "net-pop", require: false
+gem "net-smtp", require: false
+
 # Legacy Rails features, remove me!
 # responders (class level)
 gem "responders", "3.0.1"

Gemfile.lock

@@ -224,6 +224,7 @@ GEM
       fabrication (~> 2.29)
       uuid (~> 2.3, >= 2.3.8)
     diff-lcs (1.5.0)
+    digest (3.0.0)
     docile (1.4.0)
     domain_name (0.5.20190701)
       unf (>= 0.0.5, < 1.0.0)
@@ -366,6 +367,7 @@ GEM
     image_processing (1.12.2)
       mini_magick (>= 4.9.5, < 5)
       ruby-vips (>= 2.0.17, < 3)
+    io-wait (0.2.0)
     jasmine (3.10.0)
       jasmine-core (~> 3.10.0)
       phantomjs
@@ -434,6 +436,21 @@ GEM
     multipart-post (2.2.3)
     mysql2 (0.5.4)
     naught (1.1.0)
+    net-imap (0.1.1)
+      digest
+      net-protocol
+      strscan
+    net-pop (0.1.1)
+      digest
+      net-protocol
+      timeout
+    net-protocol (0.1.1)
+      io-wait
+      timeout
+    net-smtp (0.2.1)
+      digest
+      net-protocol
+      timeout
     nio4r (2.5.8)
     nokogiri (1.13.7)
       mini_portile2 (~> 2.8.0)
@@ -688,6 +705,7 @@ GEM
     ssrf_filter (1.1.1)
     state_machines (0.5.0)
     string-direction (1.2.2)
+    strscan (3.0.1)
     swd (1.3.0)
       activesupport (>= 3)
       attr_required (>= 0.0.5)
@@ -705,6 +723,7 @@ GEM
     thread_safe (0.3.6)
     tilt (2.0.10)
     timecop (0.9.5)
+    timeout (0.1.1)
     timers (4.3.3)
     toml-rb (2.1.2)
       citrus (~> 3.0, > 3.0)
@@ -822,6 +841,9 @@ DEPENDENCIES
   minitest (= 5.15.0)
   mobile-fu (= 1.4.0)
   mysql2 (= 0.5.4)
+  net-imap
+  net-pop
+  net-smtp
   nokogiri (= 1.13.7)
   omniauth (= 2.1.0)
   omniauth-rails_csrf_protection (= 1.0.1)