This re-spins #3869 with some additional copy unrolling which helps maintain SYRK performance.

After #3868, the SVE kernels represent a pretty good boost.

This re-uses ARMV8SVE as a base and I'm going to incrementally move everything to use ARMV8SVE in additional patches (as well as fix up anything that's not already in ARMV8SVE).

Add Chris Sidebottom to CONTRIBUTORS.md

parallel build fixes

Fix ?GEMMT implementation

fix missing blank in c_check

Fix x86 detection error

Convert CMAKE booleans to 0/1 values for gensymbol

Support Apple A15/M2 cpus through the existing VORTEX target

Protect CROSS_SUFFIX against spurious linebreaks from isolated dashes

fix for #3989

Export `ssyconvf` symbol

This was apparently missed in commit a836fe8ec when adding the
LAPACK 3.7.0 symbols. We noticed when adding wrappers for 3.7.0
routines in SciPy. For more details, see
https://github.com/rgommers/scipy/issues/143

Refactor ?GEBAL for readability (Reference-LAPACK PR 808)

Add Apple M1 testing via Cirrus CI

Merge back from release branch into develop to copy tag

Merge from develop branch for 0.3.23

Update with 0.3.23 changes

Fix logic bug in single-threaded C/Z SPR

Split and improve test criteria in LU computation (?GETF2)

fix division-by-zero guard in zgetf2

Fix build failures with NO_LAPACK

Improve Intel Raptor Lake detection