revert(chosen): remove composer-merge-plugin

Due to an issue with Pantheon and the now deprecated use of
composer-merge-plugin, we are removing references to it's use in order
to provide another fix for this.

References:
- https://www.drupal.org/node/3069730
- https://git.drupalcode.org/project/chosen/-/blob/4.0.x/README.txt

composer.json

@@ -19,7 +19,6 @@
     "drupal/core-recommended": "^9.2",
     "drush/drush": "^11 || ^12",
     "pantheon-systems/drupal-integrations": "^9",
-    "wikimedia/composer-merge-plugin": "^2.1",
     "yalesites-org/yalesites_profile": "*"
   },
   "require-dev": {
@@ -94,14 +93,6 @@
     "composer-exit-on-patch-failure": true,
     "patchLevel": {
       "drupal/core": "-p2"
-    },
-    "allow-plugins": {
-      "JJJ/chosen": true
-    },
-    "merge-plugin": {
-      "include": [
-        "web/modules/contrib/chosen/composer.libraries.json"
-      ]
     }
   },
   "config": {
@@ -115,9 +106,7 @@
       "composer/installers": true,
       "cweagans/composer-patches": true,
       "drupal/core-composer-scaffold": true,
-      "drupal/console-extend-plugin": true,
-      "wikimedia/composer-merge-plugin": true,
-      "oomphinc/composer-installers-extender": true
+      "drupal/console-extend-plugin": true
     }
   },
   "scripts": {

web/profiles/custom/yalesites_profile/composer.json

@@ -82,29 +82,19 @@
     "drupal/webform": "^6.2@beta",
     "drupal/wingsuit_companion": "^2.0@RC",
     "yalesites-org/atomic": "1.17.0",
-    "oomphinc/composer-installers-extender": "^2.0",
-    "wikimedia/composer-merge-plugin": "^2.1",
     "yalesites-org/yale_cas": "^1.0"
   },
   "minimum-stability": "dev",
   "prefer-stable": true,
   "config": {
-    "sort-packages": true,
-    "allow-plugins": {
-      "composer/installers": true,
-      "oomphinc/composer-installers-extender": true,
-      "wikimedia/composer-merge-plugin": true
-    }
+    "sort-packages": true
   },
   "extra": {
     "enable-patching": true,
     "composer-exit-on-patch-failure": true,
     "patchLevel": {
       "drupal/core": "-p2"
     },
-    "installer-paths": {
-      "../../../../web/core": ["type:drupal-core"]
-    },
     "patches": {
       "drupal/layout_paragraphs": {
         "save close tweaks": "https://git.drupalcode.org/project/layout_paragraphs/-/merge_requests/80.patch"