DEBIAN: apt-get 업데이트: 인증서 확인 오류

Debian 9 버전을 업그레이드하고 싶습니다. 다음 절차를 따르세요.https://www.debian.org/doc/manuals/debian-faq/uptodate.en.html

시작할 때 apt-get update다음 오류가 발생합니다.

Réception de:1 http://repo.mysql.com/apt/debian jessie InRelease [28,8 kB]
Réception de:3 http://ftp.fr.debian.org/debian buster InRelease [122 kB]
Ign:2 https://packages.dotdeb.org jessie InRelease
Err:1 http://repo.mysql.com/apt/debian jessie InRelease
  Les signatures suivantes ne sont pas valables : EXPKEYSIG 8C718D3B5072E1F5 MySQL Release Engineering <[email protected]>
Ign:3 http://ftp.fr.debian.org/debian buster InRelease
Err:4 https://packages.dotdeb.org jessie Release
  server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none
Lecture des listes de paquets... Fait
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://repo.mysql.com/apt/debian jessie InRelease: Les signatures suivantes ne sont pas valables : EXPKEYSIG 8C718D3B5072E1F5 MySQL Release Engineering <[email protected]>
W: Erreur de GPG : http://ftp.fr.debian.org/debian buster InRelease : Les signatures suivantes n'ont pas pu être vérifiées car la clé publique n'est pas disponible : NO_PUBKEY 648ACFD622F3D138 NO_PUBKEY 0E98404D386FA1D9 NO_PUBKEY DCC9EFBF77E11517
W: The repository 'http://ftp.fr.debian.org/debian buster InRelease' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: The repository 'http://packages.dotdeb.org jessie Release' does no longer 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.
root@colinweb:/# apt-get update

색상은 스크린샷을 참조하세요. apt-get 업데이트 오류 스크린샷

내 /etc/apt/sources.list콘텐츠는 다음과 같습니다.

deb http://ftp.fr.debian.org/debian/ stable main contrib

나는 또한 이 게시물 에서 이 명령을 실행해 보았습니다.https://askubuntu.com/questions/277793/getting-server-certificate-verification-failed-during-apt-get-update/277796#277796: apt-get update -o Acquire::https::mirror.ufs.ac.za::Verify-Peer=false

하지만 같은 오류가 발생합니다.