Bump net-imap from 0.4.17 to 0.4.19 (#5552)

Author: dependabot[bot]

Gemfile.lock

@@ -203,7 +203,7 @@ GEM
       activerecord (>= 5.a)
       database_cleaner-core (~> 2.0.0)
     database_cleaner-core (2.0.1)
-    date (3.3.4)
+    date (3.4.1)
     ddtrace (1.9.0)
       debase-ruby_core_source (>= 0.10.16, <= 3.2.0)
       libdatadog (~> 1.0.1.1.0)
@@ -384,7 +384,7 @@ GEM
       ruby2_keywords (~> 0.0.1)
     mutex_m (0.3.0)
     nenv (0.3.0)
-    net-imap (0.4.17)
+    net-imap (0.4.19)
       date
       net-protocol
     net-pop (0.1.2)
@@ -687,7 +687,7 @@ GEM
     thread_safe (0.3.6)
     tilt (2.3.0)
     timecop (0.9.8)
-    timeout (0.4.1)
+    timeout (0.4.3)
     ttfunk (1.7.0)
     turbo_tests (2.2.4)
       parallel_tests (>= 3.3.0, < 5)