Update CHANGELOG

Author: a2ikm

CHANGELOG.md

@@ -12,4 +12,5 @@
 - PR-52 Masato Ikeda <masato.ikeda@gmail.com> Add MongoDB 6.0 and 7.0 to CI
 - PR-53 Masato Ikeda <masato.ikeda@gmail.com> Add Ruby 3.2 to CI matrix
 - PR-54 Masato Ikeda <masato.ikeda@gmail.com> Add Ruby 3.3 to CI matrix
+- PR-57 Masato Ikeda <masato.ikeda@gmail.com> Add Ruby 3.4 to CI matrix
 - PR-59 Masato Ikeda <masato.ikeda@gmail.com> Add MongoDB 8.0 to CI matrix