use bail var in custom sign script

Author: davegarthsimpson

.github/workflows/build.yml

@@ -286,6 +286,7 @@ jobs:
       SIGNTOOL_PATH: "C:/Program Files (x86)/Windows Kits/10/bin/10.0.19041.0/x86/signtool.exe"
       WIN_CERT_PASSWORD: ${{ secrets.INSTALLER_CERT_WINDOWS_PASSWORD }}
       WIN_CERT_CONTAINER_NAME: ${{ secrets.INSTALLER_CERT_WINDOWS_CONTAINER }}
+      INTERNAL_ENABLE_WINDOWS_SIGNING: ${{ secrets.INTERNAL_ENABLE_WINDOWS_SIGNING }}
     strategy:
       matrix:
         config: ${{ fromJson(needs.select-targets.outputs.build-matrix) }}

electron-app/scripts/windowsCustomSign.js

@@ -1,7 +1,9 @@
 const childProcess = require('child_process');
 
 exports.default = async function (configuration) {
-  if (!process.env.GITHUB_ACTIONS) {
+  const enabled = !!process.env.INTERNAL_ENABLE_WINDOWS_SIGNING;
+
+  if (!enabled || !process.env.GITHUB_ACTIONS) {
     return;
   }