media-sound/r128gain: remove package

The package depends on ffmpeg-python but it doesn't exist in gentoo
repo. I don't know why it had worked in my environment, but I noticed
now it doesn't work as expected.

media-sound/loudgain is available as an alternative.

Package-Manager: Portage-3.0.6, Repoman-3.0.1
Signed-off-by: YOSHIOKA Takuma <lo48576@hard-wi.red>

media-sound/r128gain/Manifest

@@ -1 +0,0 @@
-DIST r128gain-1.0.1.tar.gz 34015 BLAKE2B bed1fcc2a82d76e41c5e65e891a0c34680785e69b146da13ea2206b30bc0b8696beb8b24b536fe2ecbfab493d53aa238e87f588aa284e16f4ec0c9c08eda74f5 SHA512 feafb2529356f345fe86d033dbd49754b47c5835a4e7bc9e2a54e1e352af08d22091d3cf8684e55be3746a5711b9c47cb0e143feb30baaefc07c1bc8a3370328

media-sound/r128gain/metadata.xml

@@ -1,14 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
-<pkgmetadata>
-	<maintainer type="person">
-		<email>lo48576@hard-wi.red</email>
-		<name>YOSHIOKA Takuma</name>
-	</maintainer>
-	<upstream>
-		<remote-id type="github">desbma/r128gain</remote-id>
-	</upstream>
-	<longdescription lang="en">
-		r128gain is a multi platform command line tool to scan your audio files and tag them with loudness metadata (ReplayGain v2 or Opus R128 gain format), to allow playback of several tracks or albums at a similar loudness level.
-	</longdescription>
-</pkgmetadata>

media-sound/r128gain/r128gain-1.0.1.ebuild

@@ -1,23 +0,0 @@
-# Copyright 1999-2020 Gentoo Authors
-# Distributed under the terms of the GNU General Public License v2
-
-EAPI=7
-
-# dev-python/crcmod-1.7-r3::gentoo does not support python3_8 as of 2020-04-10.
-PYTHON_COMPAT=( python3_{6,7} )
-DISTUTILS_USE_SETUPTOOLS=rdepend
-
-inherit distutils-r1
-
-DESCRIPTION="Fast audio loudness scanner & tagger (ReplayGain v2 / R128)"
-HOMEPAGE="https://github.com/desbma/r128gain"
-SRC_URI="https://github.com/desbma/${PN}/archive/${PV}.tar.gz -> ${P}.tar.gz"
-LICENSE="LGPL-2.1"
-SLOT="0"
-KEYWORDS="~amd64 ~x86"
-RDEPEND="${PYTHON_DEPS}
-	>=dev-python/crcmod-1.7[${PYTHON_USEDEP}]
-	>=dev-python/tqdm-4.28.1[${PYTHON_USEDEP}]
-	>=media-libs/mutagen-1.43[${PYTHON_USEDEP}]
-	virtual/ffmpeg"
-DEPEND="${RDEPEND}"