Inline single-use wayf_remember_choice coin name

# If applied, this commit will...
Remove the COIN_WAYF_REMEMBER_CHOICE constant and use the literal
string directly.

# Why is this change needed?
Prior to this change, this constant had exactly one production call
site and one test assertion, which was flagged in review as not
earning its keep as a constant.

# How does it address the issue?
This change inlines the literal 'wayf_remember_choice' at both usage
sites and removes the constant declaration.

# Provide links to any relevant tickets, articles or other resources
#2091

Author: kayjoosten

src/OpenConext/EngineBlock/Metadata/Entity/Assembler/PushMetadataAssembler.php

@@ -46,8 +46,6 @@
  */
 class PushMetadataAssembler implements MetadataAssemblerInterface
 {
-    public const COIN_WAYF_REMEMBER_CHOICE = 'wayf_remember_choice';
-
     /**
      * @var ValidatorInterface
      */
@@ -223,7 +221,7 @@ private function assembleSp(stdClass $connection)
         $properties += $this->setPathFromObjectBool([$connection, 'metadata:coin:trusted_proxy'], 'isTrustedProxy');
         $properties += $this->setPathFromObjectBool([$connection, 'metadata:coin:display_unconnected_idps_wayf'], 'displayUnconnectedIdpsWayf');
         $properties += $this->setPathFromConnectionStrictBool(
-            [$connection, 'metadata:coin:' . self::COIN_WAYF_REMEMBER_CHOICE],
+            [$connection, 'metadata:coin:wayf_remember_choice'],
             'wayfRememberChoice'
         );
 

tests/integration/OpenConext/EngineBlock/Metadata/Entity/Assembler/PushMetadataAssemblerTest.php

@@ -160,7 +160,7 @@ public function testCoins($coinName, $roleType, $parameter, $type)
 
         switch ($type) {
             case 'bool':
-                $values = $coinName === PushMetadataAssembler::COIN_WAYF_REMEMBER_CHOICE
+                $values = $coinName === 'wayf_remember_choice'
                     ? $this->validCoinValuesBoolStrictTrueOnly()
                     : $this->validCoinValuesBool();
                 break;