preact@10.15.0 newly doesn't compile with TypeScript exactOptionalPropertyTypes

[ashvinsrivatsa]

Describe the bug

preact@10.14.1 compiles when TypeScript's exactOptionalPropertyTypes tsconfig setting is enabled. preact@10.15.0 doesn't:

node_modules/preact/compat/src/index.d.ts:140:19 - error TS2430: Interface 'ForwardRefExoticComponent<P>' incorrectly extends interface 'FunctionComponent<P>'.
  Types of property 'defaultProps' are incompatible.
    Type 'Partial<P> | undefined' is not assignable to type 'Partial<P>'.
      Type 'undefined' is not assignable to type 'Partial<P>'.

140  export interface ForwardRefExoticComponent<P>
                      ~~~~~~~~~~~~~~~~~~~~~~~~~

It's complaining that FunctionComponent<P> in src/index.d.ts has defaultProps?: Partial<P> but ForwardRefExoticComponent<P> in compat/src/index.d.ts (added at b55567f) has defaultProps?: Partial<P> | undefined instead of defaultProps?: Partial<P>.

To Reproduce

npm init --yes
npm install preact@10.15.0 typescript@5.0.4
echo "import 'preact/compat'" > index.ts
npx tsc index.ts --strictNullChecks --exactOptionalPropertyTypes

Expected behavior

Ideally, preact would continue to compile with this TypeScript configuration.