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

build-js/WebpackSPDXPlugin.js

@@ -44,7 +44,7 @@ class WebpackSPDXPlugin {
 	 * @param {string} dir Directory to start checking
 	 */
 	async #findPackage(dir) {
-		if (!dir || dir === '/' || dir === '.') {
+		if (!dir || dir === '/' || dir === '.' || path.dirname(dir) === dir) {
 			return null
 		}