Drop PHP < 7.4 support

This will allow us to use flexible heredocs in test,
as well as typed properties and other goodies.

https://www.php.net/releases/7_3_0.php
https://www.php.net/releases/7_4_0.php

Author: jtojnar

.github/workflows/coding-standards.yml

@@ -16,7 +16,7 @@ jobs:
     strategy:
       matrix:
         php:
-          - "7.2"
+          - "7.4"
 
     steps:
       - name: "Checkout"

.github/workflows/continuous-integration.yml

@@ -19,8 +19,6 @@ jobs:
     strategy:
       matrix:
         php:
-          - "7.2"
-          - "7.3"
           - "7.4"
           - "8.0"
           - "8.1"
@@ -65,7 +63,7 @@ jobs:
     strategy:
       matrix:
         php:
-          - "7.4"
+          - "8.0"
 
     steps:
       - name: "Checkout"
@@ -116,7 +114,7 @@ jobs:
     strategy:
       matrix:
         php:
-          - "7.2"
+          - "7.4"
 
     steps:
       - name: "Checkout"

composer.json

@@ -24,7 +24,7 @@
         "role": "Developer (original JS version)"
     }],
     "require": {
-        "php": ">=7.2.0",
+        "php": ">=7.4.0",
         "ext-mbstring": "*",
         "psr/log": "^1.0.1 || ^2.0 || ^3.0",
         "masterminds/html5": "^2.7"