Upgrade Symfony dependencies to 6.2.1

Problem/Motivation

https://github.com/symfony/symfony/releases/tag/v6.2.1

Steps to reproduce

$ composer outdated
Direct dependencies required in composer.json:
symfony/error-handler        v6.2.0 v6.2.1 
symfony/var-dumper           v6.2.0 v6.2.1 

Transitive dependencies not required in composer.json:
phpstan/phpdoc-parser        1.13.1 1.14.0 
symfony/console              v6.2.0 v6.2.1 
symfony/dependency-injection v6.2.0 v6.2.1 
symfony/http-foundation      v6.2.0 v6.2.1 
symfony/http-kernel          v6.2.0 v6.2.1 
symfony/serializer           v6.2.0 v6.2.1 
symfony/var-exporter         v6.2.0 v6.2.1 

Proposed resolution

$ ~/.config/composer/vendor/bin/composer-lock-diff --no-links
+------------------------------+--------+--------+
| Production Changes           | From   | To     |
+------------------------------+--------+--------+
| symfony/console              | v6.2.0 | v6.2.1 |
| symfony/dependency-injection | v6.2.0 | v6.2.1 |
| symfony/error-handler        | v6.2.0 | v6.2.1 |
| symfony/http-foundation      | v6.2.0 | v6.2.1 |
| symfony/http-kernel          | v6.2.0 | v6.2.1 |
| symfony/serializer           | v6.2.0 | v6.2.1 |
| symfony/var-dumper           | v6.2.0 | v6.2.1 |
| symfony/var-exporter         | v6.2.0 | v6.2.1 |
+------------------------------+--------+--------+

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet