[Growl1234]

• Drop legacy option deprecation logic; those deprecated options are now not recognized anymore.
• Re-order CMake options to make this part look clearer.
• Drop GIT_SUBMODULES options as it's not used anywhere.
• Fix MKL linking in pyabacus CMake (use abacus::mkl)
• Use CMake's built-in FindLAPACK directly, including BLAS discovery. LAPACK::LAPACK target is available since CMake version 3.18.

The next steps will be done with a purpose of minimzing the use of custom helpers and definitions, e.g. _abacus_feature_definitions, abacus_add_target_compile_requirements etc. This would require:

• All dependency linking are target-based (what my next CMake PR(s) will do)
• Bump the minimal required version of CMake. Since ABACUS source tree and CMake handling is rather deep and complicated, this cmake_minimum_required() version bump would be substantial in order to meet the expectation (3.24+; most likely 3.27 to take use of compile context which will replace abacus_add_target_compile_requirements entirely)

This cleanup series is expected to be completed before the official 3.11 release.

[ABACUS-PR-BOT]

The generic BLAS/LAPACK discovery change drops a still-documented custom-path interface; please preserve it or provide an explicit migration.

Reviewed 6a3819b0de42 against 27c3e1065bfe through static source tracing, including affected CMake callers and CMake 3.18.6 finder contracts. git diff --check passed; configuration, builds, tests, and CI results remain unverified.

Non-blocking: Please add the exact verification commands and outcomes to the PR description, noting whether the pyabacus MKL path was exercised and which checks remain unrun.

[ABACUS-PR-BOT]

The obsolete arguments leave unused path settings in the four build helpers; the cleanup is noted inline.

Reviewed the 6a3819b0de42 → 4d16dcfdcba3 increment statically. git diff --check and the trusted governance check passed; configuration, builds, tests, and CI remain unverified.