Raise StaticArraysCore floor to 1.4.3 and Sundials to 6.5

[ChrisRackauckas-Claude]

Please ignore this PR until it has been reviewed by @ChrisRackauckas.

Raise StaticArraysCore floor from 1.4 to 1.4.3, and Sundials floor from 6 to 6.5.

Declared SAC 1.4.0 / 1.4.2 are unsat with SimpleNonlinearSolve 2.10+ (wants SAC ≥ 1.4.3). Declared Sundials 6.0 / 6.2 are unsat with SciMLBase 3.46 (wants Sundials 6.5+). Does not restack #1143 (LinearSolve 5.4).

Fail before

Isolated depot, Julia 1.10.11, Pkg.develop NonlinearSolve + pin:

RESOLVE_FAIL PKG=StaticArraysCore VER=1.4.0
 └─restricted by compatibility requirements with SimpleNonlinearSolve to versions: 1.4.3-1.4.4 — no versions left

RESOLVE_FAIL PKG=StaticArraysCore VER=1.4.2
 └─NonlinearSolveFirstOrder unsat with StaticArraysCore 1.4.2

RESOLVE_FAIL PKG=Sundials VER=6.0.0
 └─restricted by compatibility requirements with SciMLBase to versions: [2.0.0-4.10.3, 6.5.0-6.5.1] — no versions left

RESOLVE_FAIL PKG=Sundials VER=6.2.0
 └─restricted by compatibility requirements with SciMLBase to versions: [2.0.0-4.10.3, 6.5.0-6.5.1] — no versions left

Pass after

RESOLVE_OK PKG=StaticArraysCore VER=1.4.3
LOAD_OK MOD=StaticArraysCore
RESOLVE_OK PKG=Sundials VER=6.5.0

First working SAC is 1.4.3 (not 1.4.2). First working Sundials on this SciMLBase 3.46 graph is 6.5.0 (not 6.2).