ci: Remove unused ilammy/setup-nasm

[stweil]

A positive side effect of this removal is that it not only simplifies the CI rules, but also fixes this CI warning:

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: ilammy/setup-nasm@v1.

[zdenop]

AFAIR nasm is needed for building libjpeg

[stweil]

Building libjpeg works without nasm (see build log). It only reports a warning:

-- Looking for a ASM_NASM compiler - NOTFOUND
CMake Warning at simd/CMakeLists.txt:5 (message):
  SIMD extensions disabled: could not find NASM compiler.  Performance will
  suffer.
Call Stack (most recent call first):
  simd/CMakeLists.txt:57 (simd_fail)

Is this relevant? We don't want to test builds of libjpeg-turbo, but it is part of the created artifact archive file. I think it would be acceptable to have a libjpeg-turbo without SIMD optimizations there.

[DanBloomberg]

seems ok to me not to require using the SIMD compiler. with libjpeg