我收到以下错误，网站似乎缺少发布文件：
Ign:1 http://old-releases.ubuntu.com/ubuntu eoan InRelease
Ign:2 http://old-releases.ubuntu.com/ubuntu eoan-updates InRelease
Ign:3 http://old-releases.ubuntu.com/ubuntu eoan-security InRelease
Err:4 http://old-releases.ubuntu.com/ubuntu eoan Release
404 Not Found [IP: 91.189.88.248 80]
Err:5 http://old-releases.ubuntu.com/ubuntu eoan-updates Release
404 Not Found [IP: 91.189.88.248 80]
Err:6 http://old-releases.ubuntu.com/ubuntu eoan-security Release
404 Not Found [IP: 91.189.88.248 80]
Reading package lists... Done
E: The repository 'http://old-releases.ubuntu.com/ubuntu eoan Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: The repository 'http://old-releases.ubuntu.com/ubuntu eoan-updates Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: The repository 'http://old-releases.ubuntu.com/ubuntu eoan-security Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
如果我通过网络列出，我找不到 release/release.gpg：
Index of /ubuntu/dists/eoan
[ICO] Name Last modified Size
[PARENTDIR] Parent Directory -
[ ] Contents-amd64.gz 2019-10-30 13:28 39M
[ ] Contents-arm64.gz 2019-10-30 14:58 38M
[ ] Contents-armhf.gz 2019-10-30 15:27 37M
[ ] Contents-i386.gz 2019-10-30 15:57 38M
[ ] Contents-ppc64el.gz 2019-10-30 16:30 37M
[ ] Contents-s390x.gz 2019-10-30 16:57 37M
[DIR] by-hash/ 2019-04-18 14:33 -
[DIR] main/ 2019-10-10 19:18 -
[DIR] multiverse/ 2019-04-24 12:08 -
[DIR] restricted/ 2019-04-24 08:08 -
[DIR] universe/ 2019-04-24 09:13 -