remove overflowing f16 literal

[folkertdev]

r? @sayantn

The lint for overflowing f16 literals was recently enabled. This causes errors when running std with miri, see #miri > Miri test-libstd Failure (2026-01) @ 💬

  22.397776   error: literal out of range for `f16`
  0.000065        --> src/x86/avx512fp16.rs:23998:23
  0.000014         |
  0.000009   23998 |         assert_eq!(r, 65536.0);
  0.000009         |                       ^^^^^^^
  0.000008         |
  0.000008         = note: the literal `65536.0` does not fit into the type `f16` and will be converted to `f16::INFINITY`
  0.000007         = note: `#[deny(overflowing_literals)]` on by default
  0.000008
  0.000010   error: literal out of range for `f16`
  0.000009        --> src/x86/avx512fp16.rs:24005:23
  0.000008         |
  0.000008   24005 |         assert_eq!(r, 16777216.0);
  0.000007         |                       ^^^^^^^^^^
  0.000008         |
  0.000007         = note: the literal `16777216.0` does not fit into the type `f16` and will be converted to `f16::INFINITY`

[usamoi]

It's included in #1991.

[folkertdev]

Ah, great. Looks like that is ready, so that should do.