cpu: aarch64: improve memory management safety for aarch64 kernels

[Permanence-AI-Coder]

Description

The code changes in this PR were generated automatically by the Permanence AI Coder and reviewed by @fwph & @jweese. This PR updates memory allocation across several objects in the aarch64 implementation. Note that the bot is configured to add the DNNL_DISALLOW_COPY_AND_ASSIGN where it is missing; while this is redundant with the use of unique_ptr, it provides more consistency with existing code.

on-behalf-of: @permanence-ai [email protected]

General

• [X] Do all unit and benchdnn tests (make test and make test_benchdnn_*) pass locally for each commit?*
• [X] Have you formatted the code using clang-format?

• note that on our build system (AWS graviton instance) the test 172 - test_benchdnn_modeC_brgemm_ci_cpu (Subprocess aborted) is failing both on this branch AND on the main branch.