Clean changelog_unreleased

changelog_unreleased/flow/19022.md

@@ -1,19 +0,0 @@
-#### Support `readonly` as a variance annotation (#19022 by @marcoww6)
-
-Flow now accepts `readonly` as a property variance annotation, equivalent to `+` (covariant/read-only).
-
-<!-- prettier-ignore -->
-```jsx
-// Input
-type T = {
-  readonly foo: string,
-};
-
-// Prettier stable
-SyntaxError
-
-// Prettier main
-type T = {
-  readonly foo: string,
-};
-```