Adds Rust to the builder image

[kushaldas]

Status

Ready for review

Description of Changes

Version 1.52.1 of Rust.
After this is merged, we will have to push a new image. And then update #5964

Testing

• CI should be green
• @zenmonkeykstop can push a new builder image based on this

Deployment

Any special considerations for deployment? Consider both:

1. Upgrading existing production instances.
2. New installs.

Checklist

If you made changes to the server application code:

• Linting (make lint) and tests (make test) pass in the development container

If you made changes to securedrop-admin:

• Linting and tests (make -C admin test) pass in the admin development container

If you made changes to the system configuration:

• Configuration tests pass

If you added or removed a file deployed with the application:

• I have updated AppArmor rules to include the change

If you made non-trivial code changes:

• I have written a test plan and validated it for this PR

Choose one of the following:

• I have opened a PR in the docs repo for these changes, or will do so later
• I would appreciate help with the documentation
• These changes do not require documentation

If you added or updated a code dependency:

Choose one of the following:

• I have performed a diff review and pasted the contents to the packaging wiki
• I would like someone else to do the diff review

[kushaldas]

The change from @zenmonkeykstop is great. I can not still merge this. Need help in approving and also pushing a new container image.

[zenmonkeykstop]

Confirmed locally that the change builds an image with the 1.52.1 Rust toolchain in place. Gonna merge and build image.