Update electron to version 39.x

[ndoschek]

Feature Description:

Update electron to stay up-to-date and consume fixes.

• Current version: 38.4.0 (EOL Mar 10, 2026)

• Target version: 39.x

  • Target Node version: 22.21.1
    • Builds run with Node 22.x currently, so should not be an issue
  • VS Code uses 39 already with 1.107.0
  • Just FYI we have the following tickets open:
    • Implement Workaround for globalThis.navigator being defined in Node 21+ #16233
    • Ensure Theia builds with Node.js 24.x #16220

• After updating the dependency, please open a ticket for the Theia IDE to update electron and assign the toDoWithRelease and dependencies labels. This indicates that the update needs to be done in Theia IDE as well and ensures it will be addressed with the next release.