Draft: Add the "cast_lossless" lint.

Check cast_lossless section of Clippy documentation for details;

https://rust-lang.github.io/rust-clippy/master/index.html#cast_lossless

This adds the following Clippy configuration to crates;

#![deny(clippy::cast_lossless)]

And applies suggested Clippy and cargo fmt fixes.

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Side note about out of space errors

Reading through the "Advanced Configuration" documentation for GitLab shows there may be two settings that could help with space issues;

... The [[runners]] section

• limit Limit how many jobs can be handled concurrently by this token. 0 (default) means do not limit.

... Global Section

• concurrent Limits how many jobs can run concurrently. The maximum number is all defined runners. 0 does not mean unlimited.

TLDR; setting concurrent: 1 globally may allow space to be freed between jobs. However, my own tests show even after clearing caches, and manually running individual jobs, is not a guaranty to mitigating out of space errors.