minor symfony#31047 [DoctrineBridge] [DX] Update exception text in ManagerRegistry to avoid confusion. (Simperfit)

This PR was submitted for the master branch but it was merged into the 4.2 branch instead (closes symfony#31047).

Discussion
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[DoctrineBridge] [DX] Update exception text in ManagerRegistry to avoid confusion.

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | no
| New feature?  | yesish <!-- don't forget to update src/**/CHANGELOG.md files -->
| BC breaks?    | no     <!-- see https://symfony.com/bc -->
| Deprecations? | no <!-- don't forget to update UPGRADE-*.md and src/**/CHANGELOG.md files -->
| Tests pass?   | yes    <!-- please add some, will be required by reviewers -->
| Fixed tickets | symfony#29659   <!-- #-prefixed issue number(s), if any -->
| License       | MIT
| Doc PR        |

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Since the last PR was closed and the ticket is still open, taking it since it was already done by Nicolas in the comments.

Commits
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9ade232 [DoctrineBridge] [DX] Update exception text in ManagerRegistry::resetService to avoid confusion.

Author: nicolas-grekas

src/Symfony/Bridge/Doctrine/ManagerRegistry.php

@@ -46,7 +46,7 @@ protected function resetService($name)
         $manager = $this->container->get($name);
 
         if (!$manager instanceof LazyLoadingInterface) {
-            throw new \LogicException(sprintf('Resetting a non-lazy manager service is not supported. Set the "%s" service as lazy and require "symfony/proxy-manager-bridge" in your composer.json file instead.', $name));
+            throw new \LogicException('Resetting a non-lazy manager service is not supported. '.(interface_exists(LazyLoadingInterface::class) ? sprintf('Declare the "%s" service as lazy.', $name) : 'Try running "composer require symfony/proxy-manager-bridge".'));
         }
         $manager->setProxyInitializer(\Closure::bind(
             function (&$wrappedInstance, LazyLoadingInterface $manager) use ($name) {