Revert "`span`-ify `mojo/.../data_pipe.h`: Migrate `components/speech`."

This reverts commit 338ecedd.

Reason for revert: Depends on https://crrev.com/c/5598233 which was reverted.

Original change's description:
> `span`-ify `mojo/.../data_pipe.h`: Migrate `components/speech`.
>
> `span`-ification: `mojo::DataPipe[Consumer|Producer]Handle`: Migrating
> callers.  This CL `span`-ifies the callers of the APIs in
> `mojo/public/cpp/system/data_pipe.h`:
>
> * `BeginReadData` and `BeginWriteData` return (via an out parameter)
>   a `span` instead of returning a ptr+size pair.
> * `ReadData` and `WriteData` consume a `span` instead of consuming
>   a ptr+size pair.
>
> For more details see the design note here:
> https://docs.google.com/document/d/1c4NKpXwpQ9MKK1SbJ4C6MvhXI8-KJZ4jq7N4VHTHJoI/edit?usp=sharing
>
> This CL was uploaded by git cl split.
>
> R=evliu@google.com
>
> Bug: 40284755
> Change-Id: Iba157bc8ea436cbc6c50bc934fbbba21abac2ee6
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5619053


> Commit-Queue: Evan Liu <evliu@google.com>
> Auto-Submit: Łukasz Anforowicz <lukasza@chromium.org>
> Reviewed-by: Evan Liu <evliu@google.com>
> Cr-Commit-Position: refs/heads/main@{#1313157}

Bug: 40284755
Change-Id: Id863c84611963dd8b7932ee8b33409bc5fddb77c
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5619670
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Auto-Submit: Darren Shen <shend@chromium.org>
Owners-Override: Darren Shen <shend@chromium.org>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#1313161}