Implement TUF in conda

[kalefranz]

Previous/related discussion at #1395.

[github-actions]

Hi there, thank you for your contribution to Conda!

This issue has been automatically marked as stale because it has not had recent activity. It will be closed automatically if no further activity occurs.

If you would like this issue to remain open please:

1. Verify that you can still reproduce the issue in the latest version of Conda
2. Comment that the issue is still reproducible and include:

• What version of Conda you reproduced the issue on
• What OS and version you reproduced the issue on
• What steps you followed to reproduce the issue

3. It would also be helpful to have the output of the following commands available:

• conda info
• conda config --show-sources
• conda list --show-channel-urls

NOTE: If this issue was closed prematurely, please leave a comment and we will gladly reopen the issue.

In case this issue was originally about a project that is covered by the Anaconda issue tracker (e.g. Anaconda, Miniconda, packages built by Anaconda, Inc. like Anaconda Navigator etc), please reopen the issue there again.

Thanks!

[github-actions]

Hi again!

This issue has been closed since it has not had recent activity.
Please don't hesitate to leave a comment if that was done prematurely.

Thank you for your contribution.

[nealmcb]

Sorry I missed the warning. But unless this has been resolved in some other way, I still think it is an important thing to do, so this issue should be reopened.
Supply-chain protection is far more urgently needed now than ever.