minor symfony#61774 [ObjectMapper] fix documentation link (xabbuh)

This PR was merged into the 7.3 branch.

Discussion
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[ObjectMapper] fix documentation link

| Q             | A
| ------------- | ---
| Branch?       | 7.3
| Bug fix?      | no
| New feature?  | no
| Deprecations? | no
| Issues        | Fix symfony/symfony-docs#21387
| License       | MIT

Commits
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014a140 fix documentation link

Author: fabpot

src/Symfony/Component/ObjectMapper/README.md

@@ -12,7 +12,7 @@ are not covered by Symfony's
 Resources
 ---------
 
- * [Documentation](https://symfony.com/doc/current/components/object-mapper.html)
+ * [Documentation](https://symfony.com/doc/current/object_mapper.html)
  * [Contributing](https://symfony.com/doc/current/contributing/index.html)
  * [Report issues](https://github.com/symfony/symfony/issues) and
    [send Pull Requests](https://github.com/symfony/symfony/pulls)