MC-40555: PHP 7.4 support for 2.3.x

- Updated composer.json and composer.lock

Author: svera

composer.json

@@ -17,7 +17,7 @@
         }
     ],
     "require": {
-        "php": "~7.3.0",
+        "php": "~7.3.0||~7.4.0",
         "ext-bcmath": "*",
         "ext-ctype": "*",
         "ext-curl": "*",
@@ -71,12 +71,12 @@
         "laminas/laminas-uri": "^2.5.1",
         "laminas/laminas-validator": "^2.6.0",
         "laminas/laminas-view": "~2.11.2",
-        "magento/composer": "~1.5.0",
+        "magento/composer": "~1.6.0",
         "magento/magento-composer-installer": ">=0.1.11",
         "magento/zendframework1": "~1.14.2",
         "monolog/monolog": "^1.17",
         "paragonie/sodium_compat": "^1.6",
-        "pelago/emogrifier": "^2.0.0",
+        "pelago/emogrifier": "^3.1.0",
         "php-amqplib/php-amqplib": "~2.7.0||~2.10.0",
         "phpseclib/mcrypt_compat": "1.0.8",
         "phpseclib/phpseclib": "2.0.*",