bug#61637: 30.0.50; Fix Eglot tests that need HOME=~USER

[João Távora]

Basil Contovounesios <contovob@tcd.ie> writes:

> Any of the suggestions I've enumerated so far sounds plausible to me.
> But I'd appreciate some feedback on which combination if any is
> preferred before proceeding to suggest a new patchset (unless João beats
> me to it).

Eli has already said that he is OK with restoring the HOME unspoofing in
eglot--call-with-fixture unconditionally, so I've just pushed that.

'make check' now runs consistently with 0 failures on emacs-29.

But I'm still interested in your other cleanups, like more idiomatic
code, whitespace fixes, etc.  So feel free to show a patchset for that
or just push directly to emacs-29 (or master).

João