Bump electron-builder to ^26.0.0 to fix Azure signing with spaces in path (#86)

Azure Trusted Signing fails when the project path contains spaces
(e.g. C:\Users\John Doe\project). The -Files parameter passed to
Invoke-TrustedSigning was not quoted, causing PowerShell to split
the path at the space.

This was fixed upstream in electron-builder#8606 (commit a0e635c),
released in app-builder-lib v26.0.0.

Co-authored-by: Igor Gudelj <igorgudelj@users.noreply.github.com>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: igorgudelj

resources/electron/package.json

@@ -80,7 +80,7 @@
         "@vue/eslint-config-prettier": "^10.1.0",
         "cross-env": "^10.0.0",
         "electron": "^38.0.0",
-        "electron-builder": "^25.1.8",
+        "electron-builder": "^26.0.0",
         "electron-chromedriver": "^38.0.0",
         "electron-vite": "^4.0.0",
         "eslint": "^9.17.0",