Bump net-imap from 0.4.17 to 0.4.18

Bumps [net-imap](https://github.com/ruby/net-imap) from 0.4.17 to 0.4.18.
- [Release notes](https://github.com/ruby/net-imap/releases)
- [Commits](ruby/net-imap@v0.4.17...v0.4.18)

---
updated-dependencies:
- dependency-name: net-imap
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Gemfile.lock

@@ -134,7 +134,7 @@ GEM
       cucumber-messages (> 19, < 27)
     cucumber-messages (22.0.0)
     cucumber-tag-expressions (6.1.0)
-    date (3.3.4)
+    date (3.4.0)
     diff-lcs (1.5.1)
     drb (2.2.1)
     dry-configurable (1.2.0)
@@ -193,7 +193,7 @@ GEM
     minitest (5.25.1)
     multi_test (1.1.0)
     mutex_m (0.2.0)
-    net-imap (0.4.17)
+    net-imap (0.4.18)
       date
       net-protocol
     net-pop (0.1.2)
@@ -309,7 +309,7 @@ GEM
     sys-uname (1.3.0)
       ffi (~> 1.1)
     thor (1.3.2)
-    timeout (0.4.1)
+    timeout (0.4.2)
     tzinfo (2.0.6)
       concurrent-ruby (~> 1.0)
     unicode-display_width (2.6.0)