Fail to download files during bootstrap

[herquan]

I tried run command to build:
python x.py build
But failed with this error message:

Exception calling "DownloadFile" with "2" argument(s): "The request was aborted: Could not create SSL/TLS secure
channel."
At line:1 char:1
+ (New-Object System.Net.WebClient).DownloadFile('https://static.rust-l ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
    + FullyQualifiedErrorId : WebException

I checked the code and found we download bootstrap files through powershell command, which I guess is not necessary. So attachment is my fix, using urllib rather than external dependencies.

patch.diff.txt
The HEAD before my change is 06118eac4c602a22d2004c98756a95f2c5ec95d5

[ehuss]

See #55840 for the proposed fix.

[estebank]

Closing as per #55840.