每当我尝试使用此 cmd“apt-get update”时，它都会向我显示失败并建议进行更新，但是每当我尝试显示以下内容时，我都会尝试为类似问题给出的答案，但这对我不起作用。
Err:1 http://in.old-releases.ubuntu.com/ubuntu disco InRelease
Could not resolve 'in.old-releases.ubuntu.com'
Err:2 http://in.old-releases.ubuntu.com/ubuntu disco-updates InRelease
Could not resolve 'in.old-releases.ubuntu.com'
Err:3 http://in.old-releases.ubuntu.com/ubuntu disco-backports InRelease
Could not resolve 'in.old-releases.ubuntu.com'
Ign:4 http://dl.google.com/linux/chrome/deb stable InRelease
Hit:5 http://old-releases.ubuntu.com/ubuntu disco-security InRelease
Hit:6 https://brave-browser-apt-release.s3.brave.com disco InRelease
Hit:7 http://dl.google.com/linux/chrome/deb stable Release
Hit:8 https://packages.microsoft.com/repos/vscode stable InRelease
Hit:11 https://download.sublimetext.com apt/stable/ InRelease
Hit:10 https://packagecloud.io/slacktechnologies/slack/debian jessie InRelease
Reading package lists... Done
W: Target Packages (main/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list:58 and /etc/apt/sources.list.d/vscode.list:3
W: Target Packages (main/binary-all/Packages) is configured multiple times in /etc/apt/sources.list:58 and /etc/apt/sources.list.d/vscode.list:3
W: Target Translations (main/i18n/Translation-en_IN) is configured multiple times in /etc/apt/sources.list:58 and /etc/apt/sources.list.d/vscode.list:3
W: Target Translations (main/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list:58 and /etc/apt/sources.list.d/vscode.list:3
W: Target Translations (main/i18n/Translation-en_GB) is configured multiple times in /etc/apt/sources.list:58 and /etc/apt/sources.list.d/vscode.list:3
W: Target DEP-11 (main/dep11/Components-amd64.yml) is configured multiple times in /etc/apt/sources.list:58 and /etc/apt/sources.list.d/vscode.list:3
W: Target DEP-11 (main/dep11/Components-all.yml) is configured multiple times in /etc/apt/sources.list:58 and /etc/apt/sources.list.d/vscode.list:3
W: Target DEP-11-icons-small (main/dep11/icons-48x48.tar) is configured multiple times in /etc/apt/sources.list:58 and /etc/apt/sources.list.d/vscode.list:3
W: Target DEP-11-icons (main/dep11/icons-64x64.tar) is configured multiple times in /etc/apt/sources.list:58 and /etc/apt/sources.list.d/vscode.list:3
W: Target CNF (main/cnf/Commands-amd64) is configured multiple times in /etc/apt/sources.list:58 and /etc/apt/sources.list.d/vscode.list:3
W: Target CNF (main/cnf/Commands-all) is configured multiple times in /etc/apt/sources.list:58 and /etc/apt/sources.list.d/vscode.list:3
W: Failed to fetch http://in.old-releases.ubuntu.com/ubuntu/dists/disco/InRelease Could not resolve 'in.old-releases.ubuntu.com'
W: Failed to fetch http://in.old-releases.ubuntu.com/ubuntu/dists/disco-updates/InRelease Could not resolve 'in.old-releases.ubuntu.com'
W: Failed to fetch http://in.old-releases.ubuntu.com/ubuntu/dists/disco-backports/InRelease Could not resolve 'in.old-releases.ubuntu.com'
W: Some index files failed to download. They have been ignored, or old ones used instead.
W: Target Packages (main/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list:58 and /etc/apt/sources.list.d/vscode.list:3
W: Target Packages (main/binary-all/Packages) is configured multiple times in /etc/apt/sources.list:58 and /etc/apt/sources.list.d/vscode.list:3
W: Target Translations (main/i18n/Translation-en_IN) is configured multiple times in /etc/apt/sources.list:58 and /etc/apt/sources.list.d/vscode.list:3
W: Target Translations (main/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list:58 and /etc/apt/sources.list.d/vscode.list:3
W: Target Translations (main/i18n/Translation-en_GB) is configured multiple times in /etc/apt/sources.list:58 and /etc/apt/sources.list.d/vscode.list:3
W: Target DEP-11 (main/dep11/Components-amd64.yml) is configured multiple times in /etc/apt/sources.list:58 and /etc/apt/sources.list.d/vscode.list:3
W: Target DEP-11 (main/dep11/Components-all.yml) is configured multiple times in /etc/apt/sources.list:58 and /etc/apt/sources.list.d/vscode.list:3
W: Target DEP-11-icons-small (main/dep11/icons-48x48.tar) is configured multiple times in /etc/apt/sources.list:58 and /etc/apt/sources.list.d/vscode.list:3
W: Target DEP-11-icons (main/dep11/icons-64x64.tar) is configured multiple times in /etc/apt/sources.list:58 and /etc/apt/sources.list.d/vscode.list:3
W: Target CNF (main/cnf/Commands-amd64) is configured multiple times in /etc/apt/sources.list:58 and /etc/apt/sources.list.d/vscode.list:3
W: Target CNF (main/cnf/Commands-all) is configured multiple times in /etc/apt/sources.list:58 and /etc/apt/sources.list.d/vscode.list:3