Update psy/psysh requirement from ^0.11 to ^0.12

[dependabot[bot]]

Updates the requirements on psy/psysh to permit the latest version.

Release notes

Sourced from psy/psysh's releases.

PsySH v0.12.0

It's that time of year. Let's ship a major version of PsySH!

New:

• Drop support for PHP versions earlier than 7.4.
• Drop support for PHP-Parser versions earlier than 4.x.
• Remove PHP 7.0 compatibility build. For the first time in a long time, there's only one pre-built Phar!
• Include a composer lockfile in the release assets. Note that future releases will include a Composer lockfile. This one didn't because I messed up a path. Sorry 😞

And improved:

• Add support for Symfony 7 types, future-proof future Symfony deprecations.
• Add forward-compatibility for upcoming PHP-Parser 5.x.
• Clean up a bunch of deprecated code, polyfills for older PHP versions, etc.
• Remove suggested readline extension dependency; the userland implementation is a sufficient fallback!
• Improve representation of nullable types, type unions, and return types in function signatures.

PsySH v0.12.0 drops support for PHP versions older than 7.4.

Upgrade already 🙂

Commits

• 750bf03 Merge branch 'release/0.12.0'
• 4a80eed Bump to v0.12.0
• c65d832 More cleanup.
• 9137195 Indicate nullable types and type unions when formatting function signatures.
• 9fd520e Nullable return types.
• 7a3950b Clean up some todos.
• 6b4c749 Minor housekeeping.
• 230789d Fix isset test in PHP 7.x
• 72b65ee Forward-compatible PHP Parser factory support.
• 7e0785b Ignore "class not found" for PHP-Parser 5.x change
• Additional commits viewable in compare view

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