当我尝试升级到 Debian 11 Bullseye 时，我在 Debian 8 Jessie 上遇到了一个问题，问题似乎来自我已卸载的旧版本的 Letsencrypt certbot，但我仍然遇到了一些麻烦。
lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description: Debian GNU/Linux 8.11 (jessie)
Release: 8.11
Codename: jessie
这是sources_list文件的内容
纳米/etc/apt/sources.list
deb http://deb.debian.org/debian/ bullseye main
deb-src http://deb.debian.org/debian/ bullseye main
deb http://deb.debian.org/debian/ bullseye-updates main
deb-src http://deb.debian.org/debian/ bullseye-updates main
deb http://security.debian.org/debian-security bullseye-security main
deb-src http://security.debian.org/debian-security bullseye-security main
apt-get 更新
W: Failed to fetch http://ppa.launchpad.net/certbot/certbot/ubuntu/dists/jessie/main/binary-amd64/Packages 404 Not Found [IP: 185.125.190.52 80]
W: Failed to fetch http://ppa.launchpad.net/ondrej/php/ubuntu/dists/jessie/main/binary-amd64/Packages 404 Not Found [IP: 185.125.190.52 80]
W: Failed to fetch https://packages.sury.org/php/dists/jessie/main/binary-amd64/Packages server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none
E: Some index files failed to download. They have been ignored, or old ones used instead.
apt-get 升级
Err https://packages.sury.org/php/ jessie/main libpcre3 amd64 2:8.43-1+0~20190710.6+debian8~1.gbpbfc49f
server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none
E: Failed to fetch https://packages.sury.org/php/pool/main/p/pcre3/libpcre3_8.43-1+0~20190710.6+debian8~1.gbpbfc49f_amd64.deb server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?
我已经尝试过一些 apt-get clean、apt-get autoclean 和 apt-get autoremove ，它们运行时没有错误
apt-get 自动删除
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 4281 not upgraded.
有人有一些线索可以帮助我解决这个问题吗？
编辑：删除无用的文件后，/etc/apt/sources.list.d我得到了这个：
apt-get 更新
W: Failed to fetch https://packages.sury.org/php/dists/jessie/main/binary-amd64/Packages server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none
E: Some index files failed to download. They have been ignored, or old ones used instead.
apt-get 自动删除
E: /usr/share/initramfs-tools/hooks/growroot 失败并返回 1. update-initramfs: /boot/initrd.img-3.16.0-10-amd64 失败并返回 1. dpkg: 处理包 initramfs-tools 时出错（--configure）：已安装的 initramfs-tools 包安装后脚本子进程返回错误退出状态 1 处理时遇到错误：initramfs-tools E：子进程 /usr/bin/dpkg 返回错误代码（1）
已解决：删除 /etc/apt/sources.list.d 上的内容