chore: Slim unused dependencies from the project (#11541)

* Slim unused dependencies from the project

This commit enables two global lints: `unused_extern_crates` and
`unused_crate_dependencies`. The remainder of the changes chase what those lints
flagged. This should, ideally, mean we generate less dependabot updates, require
slightly less build time. I have not applied these lints to sub-crates.

Signed-off-by: Brian L. Troutwine <[email protected]>

* criterion ding

Signed-off-by: Brian L. Troutwine <[email protected]>

* incremental progress on cargo-hack

Signed-off-by: Brian L. Troutwine <[email protected]>

* more incremental progress

Signed-off-by: Brian L. Troutwine <[email protected]>

* further incremental progress

Signed-off-by: Brian L. Troutwine <[email protected]>

* slim features

Signed-off-by: Brian L. Troutwine <[email protected]>

* more incremental progress

Signed-off-by: Brian L. Troutwine <[email protected]>

* fix shutdown tests

Signed-off-by: Brian L. Troutwine <[email protected]>

* dinged by rusoto_es, assert_cmd

Signed-off-by: Brian L. Troutwine <[email protected]>

* less dings

Signed-off-by: Brian L. Troutwine <[email protected]>

* Back off unused_crate_dependencies

While this is an interesting lint it's overly strict, at least for the state of
the root crate. Our dev-dependencies get flagged quite a bit and, while we do
have inconsistent use of them, that I'm less concerned about. To resolve we'd
need to pull these into `src/lib.rs` as _ imports.

I do think the basic idea is a good one and can apply to sub-crates well
enough. Feasible to pick this back up after we slim feature flags out of the
project.

Signed-off-by: Brian L. Troutwine <[email protected]>

* indoc dings

Signed-off-by: Brian L. Troutwine <[email protected]>

* more dings

Signed-off-by: Brian L. Troutwine <[email protected]>

* remove dev-dependency dance

Signed-off-by: Brian L. Troutwine <[email protected]>

* warp is non-optional

Signed-off-by: Brian L. Troutwine <[email protected]>

* bollard non-optional

Signed-off-by: Brian L. Troutwine <[email protected]>

* more reqwest/json for es

Signed-off-by: Brian L. Troutwine <[email protected]>

* reqwest dings

Signed-off-by: Brian L. Troutwine <[email protected]>

* value ding

Signed-off-by: Brian L. Troutwine <[email protected]>