Remove purescript-string.el

It has just one utility function which is unlikely being used by
anyone. Remove it.

Author: Hi-Angel

Makefile

@@ -20,7 +20,6 @@ ELFILES = \
 	purescript-simple-indent.el \
 	purescript-sort-imports.el \
 	purescript-str.el \
-	purescript-string.el \
 	purescript-unicode-input-method.el \
 	purescript-utils.el \
 	purescript-decl-scan.el \

purescript-indent.el

@@ -89,7 +89,6 @@
 ;;; Code:
 
 (require 'purescript-vars)
-(require 'purescript-string)
 (require 'cl-lib)
 (when (< emacs-major-version 28)
   (require 'subr-x))

purescript-mode.el

@@ -37,7 +37,6 @@
 (require 'purescript-vars)
 (require 'purescript-align-imports)
 (require 'purescript-sort-imports)
-(require 'purescript-string)
 (require 'purescript-font-lock)
 (require 'cl-lib)
 (cl-eval-when 'compile (require 'find-file))