Plugins: Remove bundled plugins feature (#96490)

* remove bundled plugins

* Add echo to command

Co-authored-by: Andres Martinez Gotor <andres.martinez@grafana.com>

* remove folder entirely

* remove folder from CODEOWNERS

---------

Co-authored-by: Andres Martinez Gotor <andres.martinez@grafana.com>

package.json

@@ -50,7 +50,7 @@
     "themes-generate": "esbuild --target=es6 ./scripts/cli/generateSassVariableFiles.ts --bundle --platform=node --tsconfig=./scripts/cli/tsconfig.json | node",
     "themes:usage": "eslint . --ignore-pattern '*.test.ts*' --ignore-pattern '*.spec.ts*' --cache --plugin '@grafana' --rule '{ @grafana/theme-token-usage: \"error\" }'",
     "typecheck": "tsc --noEmit && yarn run packages:typecheck",
-    "plugins:build-bundled": "find plugins-bundled -name package.json -not -path '*/node_modules/*' -execdir yarn build \\;",
+    "plugins:build-bundled": "echo 'bundled plugins are no longer supported'",
     "watch": "yarn start -d watch,start core:start --watchTheme",
     "ci:test-frontend": "yarn run test:ci",
     "i18n:stats": "node ./scripts/cli/reportI18nStats.mjs",
@@ -437,7 +437,6 @@
     "packages": [
       "packages/*",
       "packages/!(grafana-icons)/**",
-      "plugins-bundled/internal/*",
       "public/app/plugins/*/*",
       "e2e/test-plugins/*"
     ]