Change default CLI to legacy

bin/prettier.cjs

@@ -14,11 +14,11 @@ var packageJson = require("../package.json");
 pleaseUpgradeNode(packageJson);
 
 var dynamicImport = new Function("module", "return import(module)");
-if (process.env.PRETTIER_LEGACY_CLI) {
+if (process.env.PRETTIER_EXPERIMENTAL_CLI) {
+  dynamicImport("@prettier/cli/bin");
+} else {
   var promise = dynamicImport("../src/cli/index.js").then(function runCli(cli) {
     return cli.run();
   });
   module.exports.__promise = promise;
-} else {
-  dynamicImport("@prettier/cli/bin");
 }