[issue:445] *ptex --version should not require texmf.cnf

[Karl Berry]

Hi - as of perhaps a month or so ago (I believe), (e)(u)ptex has started
looking for texmf.cnf when given --help and --version before giving the
expected output. The other engines don't look for texmf.cnf, so far as I
know.

It is better for those basic options to work without requiring
texmf.cnf, or anything else, to be installed/findable, e.g., when
running in the build directory. The result is the warning about
"configuration file texmf.cnf not found".

For example,

cd .../Build/source/Work/texk/web2c
./ptex --version
warning: kpathsea: configuration file texmf.cnf not found in these directories: [long long list omitted]
..
pTeX 3.141592653-p4.0.0 (utf8.euc) (TeX Live 2023/dev)

Compared with:
$ ./tex --version
TeX 3.141592653 (TeX Live 2023/dev)

(that is, no warning is emitted)

Thanks,
Karl