[DanglingPtr] Cherry-pick upstream build failure fix

[cdesouza-chromium]

I had to spend some significant bysecting this and it turns out rust tools don't support sanitisers, which was breaking the experimental build with dangling pointers.

Chromium change:
https://chromium.googlesource.com/chromium/src/+/b250fcef54d8631d6fc09d1936980fa81ccaf4d0

commit b250fcef54d8631d6fc09d1936980fa81ccaf4d0
Author: danakj <[email protected]>
Date:   Tue Oct 1 17:57:51 2024 +0000

    Disable PA-based features in the Rust host tools toolchain (proc macros)

    If the user explicitly turns on ASAN and use_raw_ptr_asan_unowned_impl
    we don't want to use those in the host tools toolchain. Elsewhere we
    disable ASAN in the toolchain in build/config/sanitizers/sanitizers.gni:
    ```
    if (!is_a_target_toolchain || toolchain_for_rust_host_build_tools) {
      is_asan = false
    ```

    But that leaves use_raw_ptr_asan_unowned_impl on without ASAN which then
    causes GN assertions and badness.

    The rust host tools toolchain should just use default allocators anyway
    so that the proc macro DLLs use the same allocator as the compiler that
    dlopens them.

    Bug: 40212971

Resolves

Submitter Checklist:

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  • npm run test -- brave_browser_tests, npm run test -- brave_unit_tests wiki
  • npm run presubmit wiki, npm run gn_check, npm run tslint
• Ran git rebase master (if needed)

Reviewer Checklist:

• A security review is not needed, or a link to one is included in the PR description
• New files have MPL-2.0 license header
• Adequate test coverage exists to prevent regressions
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After-merge Checklist:

• The associated issue milestone is set to the smallest version that the
  changes has landed on
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  • https://github.com/brave/brave-browser/wiki/Deviations-from-Chromium-(features-we-disable-or-remove)
  • https://github.com/brave/brave-browser/wiki/Proxy-redirected-URLs
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  • https://github.com/brave/brave-browser/wiki/QA-Guide
  • https://github.com/brave/brave-browser/wiki/P3A

Test Plan:

[brave-builds]

Released in v1.73.22