fix(state): stop adding Content-Location header for GET responses

Avoids adding a redundant `Content-Location` header in GET responses, which can cause unnecessary complications, such as issues with temporary or preview resources lacking an ID. While this behavior complies with the HTTP specification (RFC 9110), it is unnecessary and potentially problematic.

features/main/crud.feature

@@ -60,6 +60,7 @@ Feature: Create-Retrieve-Update-Delete
     Then the response status code should be 200
     And the response should be in JSON
     And the header "Content-Type" should be equal to "application/ld+json; charset=utf-8"
+    And the header "Content-Location" should not exist
     And the JSON should be equal to:
     """
     {

src/State/Processor/RespondProcessor.php

@@ -129,7 +129,7 @@ public function process(mixed $data, Operation $operation, array $uriVariables =
                     $iri = $this->iriConverter->getIriFromResource($operation->getClass(), UrlGeneratorInterface::ABS_PATH, $operation);
                 }
 
-                if ($iri) {
+                if ($iri && 'GET' !== $method) {
                     $location = \sprintf('%s.%s', $iri, $request->getRequestFormat());
                     if (isset($requestParts['query'])) {
                         $location .= '?'.$requestParts['query'];