Changelog (https://github.com/symfony/routing/compare/v6.0.7...v6.1.0-BETA1)

• feature #45803 Add EnumRequirement to help generate route requirements from a \BackedEnum (fancyweb)
• feature #45658 Avoid double encoded slashes in query parameters (usu)
• feature #45377 Bump minimum version of PHP to 8.1 (nicolas-grekas)
• feature #44615 Support the "attribute" type (alias of "annotation") in annotation loaders (fancyweb)
• feature #45075 Enrich MissingMandatoryParametersException (adrienlucas)
• feature #45054 Allow using UTF-8 parameter names (nicolas-grekas)