build: cleanup build target settings

- node14 supports es2020

Signed-off-by: Lexus Drumgold <unicornware@flexdevelopment.llc>

Author: unicornware

build.config.ts

@@ -5,7 +5,6 @@
 
 import { defineBuildConfig, type Config } from '@flex-development/mkbuild'
 import pkg from './package.json' assert { type: 'json' }
-import tsconfig from './tsconfig.build.json' assert { type: 'json' }
 
 /**
  * Build configuration options.
@@ -14,10 +13,7 @@ import tsconfig from './tsconfig.build.json' assert { type: 'json' }
  */
 const config: Config = defineBuildConfig({
   platform: 'node',
-  target: [
-    tsconfig.compilerOptions.target,
-    'node' + pkg.engines.node.replace(/^\D+/, '')
-  ],
+  target: 'node' + pkg.engines.node.replace(/^\D+/, ''),
   treeShaking: true,
   tsconfig: 'tsconfig.build.json'
 })