Use clojure-mode 5.15.1 (#3230)

https://github.com/clojure-emacs/clojure-mode/blob/v5.15.1/CHANGELOG.md

Author: vemv

CHANGELOG.md

@@ -11,6 +11,7 @@
 
 ## Changes
 
+* Upgrade clojure-mode to [5.15.1](https://github.com/clojure-emacs/clojure-mode/blob/v5.15.1/CHANGELOG.md).
 * Upgrade injected `cider-nrepl` to [0.28.5](https://github.com/clojure-emacs/cider-nrepl/releases/tag/v0.28.5).
 * [#3200](https://github.com/clojure-emacs/cider/issues/3200): Improve cider-browse-ns interface to allow selective hiding of var types as well as grouping options.  Include private vars in result list.
 * Changed default `cider-gradle-command` to `./gradlew` to use the Gradle wrapper

cider.el

@@ -12,7 +12,7 @@
 ;; Maintainer: Bozhidar Batsov <[email protected]>
 ;; URL: http://www.github.com/clojure-emacs/cider
 ;; Version: 1.5.0-snapshot
-;; Package-Requires: ((emacs "26") (clojure-mode "5.14") (parseedn "1.0.6") (queue "0.2") (spinner "1.7") (seq "2.22") (sesman "0.3.2"))
+;; Package-Requires: ((emacs "26") (clojure-mode "5.15.1") (parseedn "1.0.6") (queue "0.2") (spinner "1.7") (seq "2.22") (sesman "0.3.2"))
 ;; Keywords: languages, clojure, cider
 
 ;; This program is free software: you can redistribute it and/or modify