Ruby: fix markup in changenote

Author: nickrolfe

ruby/ql/lib/change-notes/2022-07-11-command-execution.md

@@ -2,5 +2,5 @@
 category: minorAnalysis
 ---
 * Fixed a bug causing every expression in the database to be a considered a system-command execution sink when calls to any of the following methods exist:
-  * The `spawn", "fspawn", "popen4", "pspawn", "system", "_pspawn" methods and the backtick operator from the `POSIX::spawn` gem.
+  * The `spawn`, `fspawn`, `popen4`, `pspawn`, `system`, `_pspawn` methods and the backtick operator from the `POSIX::spawn` gem.
   * The `execute_command`, `rake`, `rails_command`, and `git` methods in `Rails::Generation::Actions`.