Bump net-imap from 0.6.3 to 0.6.4 (#1249)

Bumps [net-imap](https://github.com/ruby/net-imap) from 0.6.3 to 0.6.4.
- [Release notes](https://github.com/ruby/net-imap/releases)
- [Commits](ruby/net-imap@v0.6.3...v0.6.4)

---
updated-dependencies:
- dependency-name: net-imap
  dependency-version: 0.6.4
  dependency-type: indirect
...

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

Author: dependabot[bot]

Gemfile.lock

@@ -172,7 +172,7 @@ GEM
     minitest (5.25.5)
     minitest-stub_any_instance (1.0.3)
     msgpack (1.8.0)
-    net-imap (0.6.3)
+    net-imap (0.6.4)
       date
       net-protocol
     net-pop (0.1.2)
@@ -340,7 +340,7 @@ GEM
       tty-screen (= 0.8.1)
       unicode-display_width (~> 2.2)
     thor (1.5.0)
-    timeout (0.6.0)
+    timeout (0.6.1)
     tsort (0.2.0)
     tty-screen (0.8.1)
     tzinfo (2.0.6)