version 1.4.1

Changes since 1.4.0:

• Improved performance in the ARM NEON implementation for both C and Rust callers. This affects AArch64 targets by default and ARMv7 targets that explicitly enable (and support) NEON. The size of the improvement depends on the microarchitecture, but I've benchmarked ~1.3x on a Cortex-A53 and ~1.2x on an Apple M1. Contributed by @sdlyyxy in #319.
• The MSRV is now 1.66.1 for both the blake3 crate and b3sum.