Replace renamed pkg-dir → package-directory (#43853)

In packages/subscribers-dashboard it seems this isn't needed at all. It
was apparently copy-pasted from packages/jetpack-mu-wpcom. Remove it.

For packages/jetpack-mu-wpcom we do need it. Unfortunately, since the
package went ESM-only, we have to jump through a hoop to be able to use
it from the CommonJS config file. Fortunately Webpack supports an async
function as the config.

Committed via a GitHub action: https://github.com/Automattic/jetpack/actions/runs/15542135703

Upstream-Ref: Automattic/jetpack@43cfba0

Author: anomiex

composer.lock

@@ -14,7 +14,7 @@
 		"automattic/jetpack-logo": "^3.0.5",
 		"automattic/jetpack-plans": "^0.8.0",
 		"automattic/jetpack-status": "^5.1.4",
-		"automattic/jetpack-subscribers-dashboard": "^0.1.15"
+		"automattic/jetpack-subscribers-dashboard": "^0.1.16-alpha"
 	},
 	"require-dev": {
 		"brain/monkey": "^2.6.2",

jetpack_vendor/automattic/jetpack-masterbar/composer.json

@@ -18,7 +18,7 @@
 		"automattic/jetpack-compat": "^4.0.1",
 		"automattic/jetpack-google-analytics": "^0.3.2",
 		"scssphp/scssphp": "1.12.0",
-		"automattic/jetpack-subscribers-dashboard": "^0.1.15"
+		"automattic/jetpack-subscribers-dashboard": "^0.1.16-alpha"
 	},
 	"require-dev": {
 		"yoast/phpunit-polyfills": "^4.0.0",