The full release notes can be found on GitHub, here are some highlights:

Added higher order tap (3abc4fb)

Added FactoryBuilder::lazy() method (#18823)

method (#18823) Support Redis Sentinel configuration (#18850)

Added queue prefix option (#18860)

Return PendingDispatch for Kernel::queue() (51647eb)

for (51647eb) Made RedisManager::resolve() public (#18830, eb9b99d)

public (#18830, eb9b99d) Changed email body color to match wrapper color (#18824)

Break and hyphenate long words in emails (#18827)

Set connection on model factory (#18846, 95a0663)

Fixed route parameter binding for routes with leading slashes (#18855)

Don’t call cleanParameterBag() twice during JSON request (#18840)

twice during JSON request (#18840) Force Database Migrations to use the write PDO connection (#18898)

Made the Validator’s getDisplayableAttribute() public to be accessible from within custom replacers (#18895)

Added hasValidJson() in Illuminate\Http\JsonResponse

Allow returning a string from Notification::via() (#18960)

Added a Collection::mapToGroups() method (#18949)