bug#47843: 28.0.50; Setting enable-local-variables to nil *appears* to inhibit lexical-binding (but doesn't)

[Phil Sainty]

With enable-local-variables set to nil, when editing an elisp buffer
using lexical-binding it can *seem* as though lexical-binding is not
enabled, as -*- lexical-binding: t -*- is being inhibited along with
any others.

Experimentally, Emacs appears to do the right thing, still evaluating
the code using lexical-binding.  I tested loading compiled and
uncompiled code, as well as `eval-buffer', and all of those seemed
to work correctly.

So, as far as I can, see the *only* issue is that inspecting the
local variable suggests differently.  This includes Emacs 28
displaying "elisp/d" (for dynamic binding) in the mode line instead
of "elisp/l".

Should an exception be made for this specific case, so that the
file-local variable is processed even if enable-local-variables
is nil?