Revert "partition_alloc: CMake and GN config."

This reverts commit c5f72f7a85aeeb21d7a9a12f28918970def41880.

Reason for revert:
1. An error with fetch_dawn_dependencies.py:
https://github.com/google/dawn/actions/runs/7034809858/job/19143713798
2. An error when importing Dawn in google3

I will reland with a fix for (1) and after having more understanding
of (2)

Original change's description:
> partition_alloc: CMake and GN config.
>
> Start using "partition_alloc" in Dawn using both GN and CMake.
> This is accompanied with a minimal usage to prove it works correctly.
>
> Next steps:
> - Enable BackupRefPtr and DanglingPointerDetector in tests (GN only).
> - Apply MiraclePtr rewrite.
> - (stretch) clang-tidy enforcement
>
> Bug:chromium:1464560
> Change-Id: I0b322f1e7351328287f9a14a4985c7792e2f4777
> Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/157860
> Kokoro: Kokoro <noreply+kokoro@google.com>
> Commit-Queue: Arthur Sonzogni <arthursonzogni@chromium.org>
> Reviewed-by: Corentin Wallez <cwallez@chromium.org>
> Reviewed-by: Ben Clayton <bclayton@google.com>

TBR=cwallez@chromium.org,bclayton@google.com,noreply+kokoro@google.com,dawn-scoped@luci-project-accounts.iam.gserviceaccount.com,arthursonzogni@chromium.org

Change-Id: I31e9eb33258fd0a1098a4433aeabb387f9b35702
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:1464560
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/163720
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Ben Clayton <bclayton@google.com>
Kokoro: Ben Clayton <bclayton@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>