minor symfony#31922 [Serializer] Fix DataUriNormalizer docblock & composer suggest section (ogizanagi)

This PR was merged into the 3.4 branch.

Discussion
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[Serializer] Fix DataUriNormalizer docblock & composer suggest section

| Q             | A
| ------------- | ---
| Branch?       | 3.4  <!-- see below -->
| Bug fix?      | no
| New feature?  | no <!-- please update src/**/CHANGELOG.md files -->
| BC breaks?    | no     <!-- see https://symfony.com/bc -->
| Deprecations? | yes/no <!-- please update UPGRADE-*.md and src/**/CHANGELOG.md files -->
| Tests pass?   | yes    <!-- please add some, will be required by reviewers -->
| Fixed tickets | N/A   <!-- #-prefixed issue number(s), if any -->
| License       | MIT
| Doc PR        | N/A

See
https://github.com/symfony/symfony/blob/9691519ca46511005bc701ca93c2973923952034/src/Symfony/Component/Serializer/Normalizer/DataUriNormalizer.php#L135-L139

Commits
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51b6bd8 [Serializer] Fix DataUriNormalizer docblock & composer suggest section

Author: nicolas-grekas

src/Symfony/Component/Serializer/Normalizer/DataUriNormalizer.php

@@ -32,7 +32,7 @@ class DataUriNormalizer implements NormalizerInterface, DenormalizerInterface
     ];
 
     /**
-     * @var MimeTypeGuesserInterface
+     * @var MimeTypeGuesserInterface|null
      */
     private $mimeTypeGuesser;
 

src/Symfony/Component/Serializer/composer.json

@@ -44,7 +44,7 @@
         "symfony/yaml": "For using the default YAML mapping loader.",
         "symfony/config": "For using the XML mapping loader.",
         "symfony/property-access": "For using the ObjectNormalizer.",
-        "symfony/http-foundation": "To use the DataUriNormalizer.",
+        "symfony/http-foundation": "For using a MIME type guesser within the DataUriNormalizer.",
         "doctrine/annotations": "For using the annotation mapping. You will also need doctrine/cache.",
         "doctrine/cache": "For using the default cached annotation reader and metadata cache."
     },