Bump net-imap from 0.5.0 to 0.5.1 (#4052)

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

Gemfile.lock

@@ -261,7 +261,7 @@ GEM
     mini_mime (1.1.5)
     minitest (5.25.1)
     nenv (0.3.0)
-    net-imap (0.5.0)
+    net-imap (0.5.1)
       date
       net-protocol
     net-pop (0.1.2)