Move a few straggling dependencies to workspace Cargo.toml

[sffc]

As part of the 2.0.0-beta1 release checklist, I found a few crates that have dependencies that aren't in the workspace:

• components/normalizer/fuzz
• ffi/ecma402
• ffi/freertos
• tools/benchmark/macros
• tools/benchmark/memory
• tools/make/diplomat-coverage
• utils/bies
• utils/env_preferences
• utils/potential_utf (dev deps)

Maybe some of these should start using workspace dependencies. For ones that don't, maybe explicitly say that they are excluded in the release checklist.

[robertbastian]

• components/normalizer/fuzz

This is not part of the workspace, and is publish=false

• ffi/ecma402
• ffi/freertos

I purposely didn't use workspace deps for the ecma402 traits and freertos, because no other crates should ever need them, and it's useful to be able to figure out the version without going to workspace deps.

• tools/benchmark/macros
• tools/benchmark/memory
• tools/make/diplomat-coverage

It's nice for the workspace list to match the deps of ICU4X (icu/icu_capi/icu4x-datagen), and to not have random tool deps in them.

• utils/bies
• utils/env_preferences

Same here, these are not ICU4X deps...

• utils/potential_utf (dev deps)

Sure

[sffc]

"I found a few crates that have dependencies that aren't in the workspace"

For example, the crate at tools/benchmark/macros depends on dhat = { version = "0.3", optional = true }. This issue is to decide whether that should be dhat = { workspace = true, optional = true } (I think it should) and then implement it across the crates listed above.