Fixed flowjs ts3.1 event handlers types and TS2306 error (#42470)
Fixed flowjs ts3.1 event handlers types and TS2306 error (#42470)

* fix typo/copy-paste error in flowjs

* Fix Error TS2306 ("flowjs/index.d.ts not a module") in flowjs/ts3.1

* fix linter

markogresak/DefinitelyTyped,mcliment/DefinitelyTyped,georgemarshall/DefinitelyTyped,dsebastien/DefinitelyTyped,georgemarshall/DefinitelyTyped,dsebastien/DefinitelyTyped,georgemarshall/DefinitelyTyped,georgemarshall/DefinitelyTyped