minor symfony#31637 Fix typo (thewilkybarkid)

This PR was merged into the 4.3 branch.

Discussion
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Fix typo

| Q             | A
| ------------- | ---
| Branch?       | 4.3
| Bug fix?      | no
| New feature?  | no <!-- please update src/**/CHANGELOG.md files -->
| BC breaks?    | no     <!-- see https://symfony.com/bc -->
| Deprecations? | no <!-- please update UPGRADE-*.md and src/**/CHANGELOG.md files -->
| Tests pass?   | yes    <!-- please add some, will be required by reviewers -->
| Fixed tickets |   <!-- #-prefixed issue number(s), if any -->
| License       | MIT
| Doc PR        | <!-- required for new features -->

(Not sure if this was copied/pasted from somewhere.)

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Commits
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b27b419 Fix typo

Author: fabpot

src/Symfony/Contracts/Service/composer.json

@@ -1,7 +1,7 @@
 {
     "name": "symfony/service-contracts",
     "type": "library",
-    "description": "Generic abstractions related to writting services",
+    "description": "Generic abstractions related to writing services",
     "keywords": ["abstractions", "contracts", "decoupling", "interfaces", "interoperability", "standards"],
     "homepage": "https://symfony.com",
     "license": "MIT",