chore: migrate to new versions of prosemirror packages (#2854)

* refactor: upgrade prosemirror packages to new typescript versions

* refactor: migrate to new typings from prosemirror

* style: fix linting issues

* style: fix linting issues

* style: fix linting issues

* fix(ci): fix build process by reimplement filterTransaction

* fix(extension-test): fix broken build because of wrong output file names

* fix: fix prosemirror-tables not being bundled correctly for ES6

* fix: move to prosemirror-tables-contently until es6 build is working

* fix: fix tests for youtube

* fix: fix youtube test

* fix(demos): fix demos build

packages/extension-placeholder/src/placeholder.ts

@@ -41,7 +41,7 @@ export const Placeholder = Extension.create<PlaceholderOptions>({
             const decorations: Decoration[] = []
 
             if (!active) {
-              return
+              return null
             }
 
             doc.descendants((node, pos) => {