Bump net-imap to v0.5.11

#407 (comment)

Author: k0kubun

benchmarks/lobsters/Gemfile

@@ -59,10 +59,6 @@ gem "sitemap_generator" # for better search engine indexing
 gem "svg-graph", require: 'SVG/Graph/TimeSeries' # for charting, note workaround in lib/time_series.rb
 gem 'rack-attack' # rate-limiting
 
-# Avoid using v0.5.7 ~ v0.5.10 that have bad use of Ractor.make_sharable.
-# TODO: Use v0.5.11+ once it's released with https://github.com/ruby/net-imap/pull/525.
-gem "net-imap", "< 0.5.7"
-
 group :test, :development do
   gem 'capybara'
   gem 'database_cleaner'

benchmarks/lobsters/Gemfile.lock

@@ -153,7 +153,7 @@ GEM
     mini_mime (1.1.5)
     mini_portile2 (2.8.9)
     minitest (5.25.5)
-    net-imap (0.5.6)
+    net-imap (0.5.11)
       date
       net-protocol
     net-pop (0.1.2)
@@ -349,7 +349,6 @@ DEPENDENCIES
   json
   mail
   memory_profiler
-  net-imap (< 0.5.7)
   nokogiri (>= 1.13.9)
   oauth
   ostruct