Update Symfony and PHP dependencies (#57)

- Remove support for PHP 7.3
- Remove support for Symfony 3.x, 4.x except 4.4, 5.x except 5.4

Author: theofidry

.github/workflows/ci.yaml

@@ -14,7 +14,6 @@ jobs:
             fail-fast: true
             matrix:
                 php:
-                    - "7.3"
                     - "7.4"
                     - "8.0"
                     - "8.1"

composer.json

@@ -15,18 +15,18 @@
     ],
 
     "require": {
-        "php": "^7.3 || ^8.0",
-        "symfony/console": "^3.0 || ^4.0 || ^5.0 || ^6.0",
-        "symfony/dependency-injection": "^3.0 || ^4.1.12 || ^5.0 || ^6.0",
-        "symfony/process": "^3.0 || ^4.0 || ^5.0 || ^6.0",
+        "php": "^7.4 || ^8.0",
+        "symfony/console": "^4.4 || ^5.4 || ^6.0",
+        "symfony/dependency-injection": "^4.4 || ^5.4 || ^6.0",
+        "symfony/process": "^4.4 || ^5.4 || ^6.0",
         "webmozart/assert": "^1.5",
         "psr/log": "^1.1"
     },
     "require-dev": {
         "ext-json": "*",
         "friendsofphp/php-cs-fixer": "^2.15",
         "phpunit/phpunit": "^8.4",
-        "symfony/framework-bundle": "^3.0 || ^4.1 || ^5.0 || ^6.0"
+        "symfony/framework-bundle": "^4.4 || ^5.4 || ^6.0"
     },
 
     "autoload": {