Brand new/Awesome `SchemaPrinter` 😋

☣	Breaking changes
🔥	Something cool

Features

• core: Added Subject::getObservers(). (eb59a63)
• eloquent: Added ModelHelper::isSoftDeletable() helper. (b254288)
• eloquent: Result of ModelHelper::isRelation() will be cached (cache can be reset by ModelHelper::resetCache()) (a63f272)
• graphql: Added GraphQLExpectedSchema that can be used with assertGraphQLSchemaEquals() to check used/unused types and directives. (72fd9a9)
• graphql: 🔥 Awesome SchemaPrinter with directives, filtering, advanced formatting, and more. The assertGraphQLSchemaEquals() also updated to use it. (f9e0b35) ☣
• graphql: Minimal version of "nuwave/lighthouse" set to "^5.6.1" (required to print repeatable directives). (e694b7d) ☣

Bug Fixes

• formatter: Formatter::forLocale()/Formatter::forTimezone() will not lose timezone/locale. (940ed7b)
• testing: Override will check usages in assertPostConditions() instead of beforeApplicationDestroyed() ("Lock wait timeout exceeded" fix). (95649d9)

Code Refactoring

• core: Subject methods will return self instead of void. (7d80539) ☣
• core: Class Subject converted into interface, all methods moved into new class Dispatcher. (e7bef00) ☣