bpo-42874: Remove grep -qE options for Solaris 10 compatibility (GH-24200)

According to [bpo-42874](), some versions of grep do not support the `-q` and `-E` options. Although both options are used elsewhere in the configure script, this particular bit of validation can be achieved without them,
so there's no real harm in using a grep call with no flags.

Would be good to get some people taking advantage of the `--with-tzpath` arguments in the wild to try this out.. Local testing seems to indicate that this does the same thing, but I don't know that we have any buildbots using this option. Maybe @pablogsal?

[bpo-42874]():