ci: Add terser-webpack-plugin to the dev dependency definition, given it is used there

Assisted-by: ClaudeCode:claude-sonnet-5
Signed-off-by: Andy Scherzinger <info@andy-scherzinger.de>

Author: AndyScherzinger

package-lock.json

@@ -72,6 +72,7 @@
 		"eslint-webpack-plugin": "^5.0.2",
 		"jsdom": "^28.1.0",
 		"stylelint-webpack-plugin": "^5.0.1",
+		"terser-webpack-plugin": "^5.3.11",
 		"vitest": "^4.0.18"
 	},
 	"engines": {