Temporarily remove optional chaining in nesting plugin (#7077)

* remove optional chaining

This breaks on Node versions lower than version 13. Normally we
transpile everything, but we currently don't do this for the nesting
plugin since it is not really part of the `src` folder.

Will get this fixed in a better way, but for now this is a quick fix to
get everything working again!

* update changelog

Author: RobinMalfait

CHANGELOG.md

@@ -7,7 +7,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
-- Nothing yet!
+### Fixed
+
+- Temporarily remove optional chaining in nesting plugin ([#7077](https://github.com/tailwindlabs/tailwindcss/pull/7077))
 
 ## [3.0.14] - 2022-01-14
 

nesting/plugin.js

@@ -16,7 +16,7 @@ module.exports = function nesting(opts = postcssNested) {
     let plugin = (() => {
       if (
         typeof opts === 'function' ||
-        (typeof opts === 'object' && opts?.hasOwnProperty('postcssPlugin'))
+        (typeof opts === 'object' && opts.hasOwnProperty('postcssPlugin'))
       ) {
         return opts
       }