fix: remove signature from electron binary before we rebrand it (#4721)

Author: karanbirsingh

pipeline/unified/download-electron-mirror.yaml

@@ -3,3 +3,7 @@
 steps:
     - script: yarn download:electron-mirror:binaries
       displayName: download custom electron binaries
+
+    - powershell: '& "C:\Program Files (x86)\Windows Kits\10\App Certification Kit\signtool.exe" remove /s node_modules/electron/dist/electron.exe'
+      displayName: remove signing from electron binary before rebranding
+      condition: eq(variables['Agent.OS'], 'Windows_NT')