Symfony version(s) affected: 4.2.7

Description
When using routes parameters (like format), there is an issue when using a trailing slash:

How to reproduce
I've created a reproduction repo that contains two routes:

• /foo
• /bar.{_format} where _format = html by default

Reproduction steps:

• run php bin/console server:start
• open http://127.0.0.1:8000/foo
• open http://127.0.0.1:8000/foo/
• open http://127.0.0.1:8000/bar
• open http://127.0.0.1:8000/bar/ <-- only this one fails
• open http://127.0.0.1:8000/bar.html
• open http://127.0.0.1:8000/bar.html/

Additional context
I first thought it was because of API Platform (I'm faced this issue on a URL generated by API Platform), but after some investigations it seems the issues is due to parameters.

Note this has been working fine in Symfony 4.2.4, 4.2.5 and 4.2.6.

Thanks!