Travis CI: Windows builds are failing because 'dotnetfx' requires a reboot

https://travis-ci.com/refack/GYP3
```
Packages requiring reboot:
 - dotnetfx (exit code 3010)
The recent package changes indicate a reboot is necessary.
 Please reboot at your earliest convenience.
The command "choco install python3 visualstudio2019buildtools visualstudio2019-workload-vctools" failed and exited with 194 during .
Your build has been stopped.
```