deps: Deduplicate futures, disable features & improve consistency (#42678)

- Remove deps on `futures@0.1.31`. Update deny
- Remove `compat` features of futures. This is not used anywhere and
introduces duplication.
- Move deps to root. Fix weird field like `futures = { version = "0.3",
package = "futures" }`. Use 0.3 instead of minor version as recommended
by
[README](https://github.com/rust-lang/futures-rs/tree/master/futures-executor#readme)
- Use workspace version for sha2
- Update `futures` & `futures-executor` to 0.3.32
- Disable default features of `futures`: this decreases binary size by
12KB in release.

Testing: Existing UT.

---------

Signed-off-by: Euclid Ye <yezhizhenjiakang@gmail.com>

deny.toml

@@ -214,7 +214,6 @@ skip = [
     # These need to be investigated separately to see if the duplication can be
     # avoided.
     "libloading",
-    "futures",
     "cfg-expr",
     "system-deps",
     "target-lexicon",