Merged PR 35965: Update minimum PHP requirement to 7.2

## What's being changed

The minimum PHP requirement for using our Magento connectors is now 7.2.

## Why it's being changed

PHP 7.2 is supported for all 2.3+ versions, so this doesn't affect the Magento versions we support. However, even PHP 7.3 is now end of life. This is a practical step to reduce our exposure to errors now that we also support PHP 8.1.

## How to review / test this change

- Switch to PHP 7.2
- Run `composer update`
- Run `bin/magento setup:upgrade`

Related work items: #167169

CHANGELOG.md

@@ -9,6 +9,7 @@
 - Errors relating to unsubscribing contacts who are already suppressed in Dotdigital will now not trigger a System Alert.
 - We've improved the performance of the `InsertEmailContactTableCustomerSales` migration type.
 - The structure of our data migration code has been refactored to use additional abstract classes.
+- PHP 7.2 is now a minimum requirement for running this module. 
 
 # 4.14.1
 

README.md

@@ -4,7 +4,7 @@
 [![license](https://img.shields.io/github/license/mashape/apistatus.svg)](LICENSE.md)
 
 ## Requirements
-- PHP 7.1+
+- PHP 7.2+
 - Magento 2.3+ 
     - Magento 2.1.x is compatible up to version 4.2.0-p1
     - Magento 2.2.x is compatible up to version 4.13.x

composer.json

@@ -14,7 +14,7 @@
     "dotmailer/dotmailer-magento2-extension": "*"
   },
   "require": {
-    "php": "^7.1||^8.0",
+    "php": "^7.2||^8.0",
     "magento/framework": ">=101 <104",
     "magento/module-newsletter": "100.*",
     "magento/module-review": ">=100 <102",