I can't find release-upgrade when I input "sudo do-release-upgrade"

[Manchester]

在更新您的软件包信息后，无法定位必要的软件包“ubuntu-minimal”。这可能是因为您没有在软件源中使用官方镜像，或您正在使用的镜像负载过重。请查看
/etc/apt/sources.list 文件了解软件源当前的配置列表。
如果是因为镜像服务器负载过重，您可能需要稍后重试升级。

ProblemType: Bug
DistroRelease: Ubuntu 21.04
Package: ubuntu-release-upgrader-core 1:21.04.17
ProcVersionSignature: Ubuntu 5.11.0-37.41-generic 5.11.22
Uname: Linux 5.11.0-37-generic x86_64
ApportVersion: 2.20.11-0ubuntu65.3
Architecture: amd64
CasperMD5CheckResult: unknown
CrashDB: ubuntu
Date: Fri Oct 15 14:44:48 2021
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to hirsute on 2021-10-15 (0 days ago)
VarLogDistupgradeAptlog:
 Log time: 2021-10-15 14:43:55.592359
 Log time: 2021-10-15 14:44:00.159852
 Log time: 2021-10-15 14:44:48.414973
 Log time: 2021-10-15 14:44:50.456945