Remove most pnpm hoisting, fix phantom deps (#24096)

We've long had pnpm's public hoisting disabled, but it also privately
hoists everything into `node_modules/.pnpm/node_modules/` for
compatibility with packages that have undeclared dependencies. Let's
disable most of that private hoisting and see what turns up.

Changes of note:

* We still hoist a bunch of eslint plugins (and one prettier plugin) as
  untangling that mess seems like enough work to put off for later.
* Only a few upstream packages have bugs that need working around:
  * `@mdx-js/loader`: mdx-js/mdx#2019
  * `@automattic/components`: Missing dep on `@wordpress/base-styles`.
	And the next version will probably be unusable for us due to added
	`i18n-calypso`.
  * `@automattic/popup-monitor`: Missing dep on `events`.
  * markdown-it`: Missing dep on `punycode`.
    markdown-it/markdown-it#230
  * `@samverschueren/stream-to-observable`: Outdated dep on `any-observable`.
    SamVerschueren/stream-to-observable#9
    Hacking around that should also fix p1649254510834369-slack-CBG1CP4EN.
  * `git-node-fs`: Missing peer dep on `js-git`.
    creationix/git-node-fs#8
* `fetch-mock`'s peer dep on `node-fetch` is optional, but only because
  they also allow running in-browser. It's required for node.
* Added `webpack-cli` alongside `webpack` everywhere to make sure
  p1650571211251179-slack-CBG1CP4EN is fixed. Dropped Webpack entirely
  from Boost instead though, they don't use it.
* Had our webpack-config package point to its own copy of
  `@babel/runtime` instead of making that a peer dep.
* Jetpack's extensions tests use a ton of `@wordpress/` packages that
  weren't being directly depended on.

Committed via a GitHub action: https://github.com/Automattic/jetpack/actions/runs/2234009376

Author: anomiex

CHANGELOG.md

@@ -9,6 +9,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 This is an alpha version! The changes listed here are not final.
 
+### Added
+- Add missing JavaScript dependencies.
+
 ### Changed
 - My Jetpack: remove duplicated site suffix stored on rawUrl. Use siteSuffix instead.
 

package.json

@@ -68,6 +68,7 @@
 		"sass-loader": "12.4.0",
 		"storybook-addon-mock": "2.0.2",
 		"typescript": "4.3.5",
-		"webpack": "5.65.0"
+		"webpack": "5.65.0",
+		"webpack-cli": "4.9.1"
 	}
 }