Remove duplicate php requirement check

sodium.install

@@ -10,18 +10,10 @@
  *
  * Verifies that module requirements are met.
  */
-function sodium_requirements($phase) {
+function sodium_requirements(string $phase): array {
   $requirements = [];
 
-  if ($phase == 'install') {
-    // Verify that the PHP version is at least 7.2.
-    if (PHP_VERSION_ID < 70200) {
-      $requirements['php_version'] = [
-        'description' => t('Sodium requires PHP version 7.2 or greater.'),
-        'severity' => REQUIREMENT_ERROR,
-      ];
-    }
-
+  if ($phase === 'install') {
     // Verify that the Halite PHP library is available.
     if (!class_exists('\ParagonIE\Halite\Halite')) {
       $requirements['halite_library'] = [