Bump net-imap from 0.6.3 to 0.6.4

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
...

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

Author: dependabot[bot]

Gemfile.lock

@@ -318,7 +318,7 @@ GEM
     mutex_m (0.3.0)
     net-http (0.9.1)
       uri (>= 0.11.1)
-    net-imap (0.6.3)
+    net-imap (0.6.4)
       date
       net-protocol
     net-pop (0.1.2)
@@ -966,7 +966,7 @@ CHECKSUMS
   multi_xml (0.8.1) sha256=addba0290bac34e9088bfe73dc4878530297a82a7bbd66cb44dcd0a4b86edf5a
   mutex_m (0.3.0) sha256=cfcb04ac16b69c4813777022fdceda24e9f798e48092a2b817eb4c0a782b0751
   net-http (0.9.1) sha256=25ba0b67c63e89df626ed8fac771d0ad24ad151a858af2cc8e6a716ca4336996
-  net-imap (0.6.3) sha256=9bab75f876596d09ee7bf911a291da478e0cd6badc54dfb82874855ccc82f2ad
+  net-imap (0.6.4) sha256=9a5598c67a3022c284d98430ef1d4948e7dbdb62596f61081ea8ca933270a02b
   net-pop (0.1.2) sha256=848b4e982013c15b2f0382792268763b748cce91c9e91e36b0f27ed26420dff3
   net-protocol (0.2.2) sha256=aa73e0cba6a125369de9837b8d8ef82a61849360eba0521900e2c3713aa162a8
   net-smtp (0.5.1) sha256=ed96a0af63c524fceb4b29b0d352195c30d82dd916a42f03c62a3a70e5b70736