deps: update to bytecount 0.5

bytecount now uses runtime dispatch for enabling SIMD, which means we can
no longer need the avx-accel features. We remove it from ripgrep since the
next release will be a minor version bump, but leave them as no-ops for
the crates that previously used it.

Cargo.toml

@@ -72,7 +72,6 @@ serde = "1.0.77"
 serde_derive = "1.0.77"
 
 [features]
-avx-accel = ["grep/avx-accel"]
 simd-accel = ["grep/simd-accel"]
 pcre2 = ["grep/pcre2"]