Add style-level check for blank newline after EAPI

[thesamesam]

In proxy-maint (and many other projects), we ask that folks add a blank newline after EAPI. This could be a style-level check.

Bad:

# Copyright 1999-2023 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2

EAPI=8
inherit foo

Good:

# Copyright 1999-2023 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2

EAPI=8

inherit foo