Bump net-imap in /test/truffle/gems/default-bundled-gems

Bumps [net-imap](https://github.com/ruby/net-imap) from 0.4.19 to 0.4.20.
- [Release notes](https://github.com/ruby/net-imap/releases)
- [Commits](ruby/net-imap@v0.4.19...v0.4.20)

---
updated-dependencies:
- dependency-name: net-imap
  dependency-version: 0.4.20
  dependency-type: direct:production
...

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

Author: dependabot[bot]

test/truffle/gems/default-bundled-gems/Gemfile

@@ -74,7 +74,7 @@ gem "debug", "1.9.2"
 gem "matrix", "0.4.2"
 gem "minitest", "5.20.0"
 gem "net-ftp", "0.3.4"
-gem "net-imap", "0.4.19"
+gem "net-imap", "0.4.20"
 gem "net-pop", "0.1.2"
 gem "net-smtp", "0.4.0.1"
 gem "power_assert", "2.0.3"

test/truffle/gems/default-bundled-gems/Gemfile.lock

@@ -44,7 +44,7 @@ GEM
       time
     net-http (0.4.1)
       uri
-    net-imap (0.4.19)
+    net-imap (0.4.20)
       date
       net-protocol
     net-pop (0.1.2)
@@ -159,7 +159,7 @@ DEPENDENCIES
   mutex_m (= 0.2.0)
   net-ftp (= 0.3.4)
   net-http (= 0.4.1)
-  net-imap (= 0.4.19)
+  net-imap (= 0.4.20)
   net-pop (= 0.1.2)
   net-protocol (= 0.2.2)
   net-smtp (= 0.4.0.1)