Drop core-js 2 support (#11751)

* breaking(preset-env): remove corejs 2 plugin

* test(preset-env): revise for corejs default value changes

* test(preset-env): remove unused core-js 2 tests

* breaking(transform-runtime): remove core-js 2 support

* test(transform-runtime): revise for core-js 3

* test(transform-runtime): remove core-js 2 related tests

* breaking(compat-data): remove core-js 2 compat data

* breaking: remove corejs2 compat data proxy

* chore: do not clean and force publish runtime-corejs2

* address review comments

* Update packages/babel-plugin-transform-runtime/src/index.js

Co-authored-by: Nicolò Ribaudo <nicolo.ribaudo@gmail.com>

Co-authored-by: Nicolò Ribaudo <nicolo.ribaudo@gmail.com>

Makefile

@@ -2,7 +2,7 @@ FLOW_COMMIT = a1f9a4c709dcebb27a5084acf47755fbae699c25
 TEST262_COMMIT = 058adfed86b1d4129996faaf50a85ea55379a66a
 TYPESCRIPT_COMMIT = 5fc917be2e4dd64c8e9504d36615cd7fbfdd4cd3
 
-FORCE_PUBLISH = "@babel/runtime,@babel/runtime-corejs2,@babel/runtime-corejs3,@babel/standalone"
+FORCE_PUBLISH = "@babel/runtime,@babel/runtime-corejs3,@babel/standalone"
 
 # Fix color output until TravisCI fixes https://github.com/travis-ci/travis-ci/issues/7967
 export FORCE_COLOR = true
@@ -262,9 +262,7 @@ clean-lib:
 
 clean-runtime-helpers:
 	rm -f packages/babel-runtime/helpers/**/*.js
-	rm -f packages/babel-runtime-corejs2/helpers/**/*.js
 	rm -f packages/babel-runtime-corejs3/helpers/**/*.js
-	rm -rf packages/babel-runtime-corejs2/core-js
 
 clean-all:
 	rm -rf node_modules