fix(insider): test before using getPreferredSystemLanguages

closes #1335

patches/insider/system-languages.patch

@@ -0,0 +1,18 @@
+diff --git a/src/main.js b/src/main.js
+index 63f8c56..a6b7d44 100644
+--- a/src/main.js
++++ b/src/main.js
+@@ -575,6 +575,10 @@ async function resolveNlsConfiguration() {
+ 		 */
+-		// @ts-ignore API not yet available in the official Electron
+-		let appLocale = ((product.quality === 'insider' || product.quality === 'exploration') && app?.getPreferredSystemLanguages()?.length) ?
++		let appLocale = app.getLocale();
++		if (product.quality === 'insider' || product.quality === 'exploration') {
+ 			// @ts-ignore API not yet available in the official Electron
+-			app.getPreferredSystemLanguages()[0] : app.getLocale();
++			if (app.getPreferredSystemLanguages && app?.getPreferredSystemLanguages()?.length) {
++				// @ts-ignore API not yet available in the official Electron
++				appLocale = app.getPreferredSystemLanguages()[0];
++			}
++		}
+ 		if (!appLocale) {

product.json

@@ -157,11 +157,13 @@
       "documentFiltersExclusive"
     ],
     "GitHub.vscode-pull-request-github": [
+      "contribCommentThreadAdditionalMenu",
       "tokenInformation",
       "commentsResolvedState",
       "contribShareMenu",
       "contribCommentPeekContext",
-      "treeItemCheckbox"
+      "treeItemCheckbox",
+      "codiconDecoration"
     ],
     "GitHub.copilot": [
       "inlineCompletionsAdditions"