Remove 20.10

[tianon]

With the release of v20.10.25, the 20.10 branch of the upstream Moby project is no longer going to have builds available on https://download.docker.com/ (where the builds for this image come from).

This removes our 20.10 versions accordingly.

(I updated our entrypoint code that accounts for https://github.com/docker-library/docker/issues/318 to apply to non-20.10 versions now as well, because they're also affected and we just hadn't noticed yet and fixed the conditional. :see_no_evil:)

[tianon]

Diff of `generate-stackbrew-library.sh` generation, for the avoidance of doubt:

```diff $ diff -u --color <(bashbrew cat docker) <(bashbrew cat <(./generate-stackbrew-library.sh)) --- /dev/fd/63 2023-05-15 15:47:53.265217296 -0700 +++ /dev/fd/62 2023-05-15 15:47:53.269217331 -0700 @@ -9,7 +9,7 @@ Tags: 24.0.0-rc.4-dind, 24-rc-dind, rc-dind, 24.0.0-rc.4-dind-alpine3.18, 24.0.0-rc.4, 24-rc, rc, 24.0.0-rc.4-alpine3.18 Architectures: amd64, arm64v8 -GitCommit: 38d8c1da029024c9f6cbfb306bdaf8461b3b5914 +GitCommit: a3ca225e9c0e568cf87a7b60c951b939c3964c91 Directory: 24-rc/dind Tags: 24.0.0-rc.4-dind-rootless, 24-rc-dind-rootless, rc-dind-rootless @@ -45,7 +45,7 @@ Tags: 23.0.6-dind, 23.0-dind, 23-dind, dind, 23.0.6-dind-alpine3.18, 23.0.6, 23.0, 23, latest, 23.0.6-alpine3.18 Architectures: amd64, arm64v8 -GitCommit: 3f698e446071ef052c3bd70fe0322493dbfd5103 +GitCommit: a3ca225e9c0e568cf87a7b60c951b939c3964c91 Directory: 23.0/dind Tags: 23.0.6-dind-rootless, 23.0-dind-rootless, 23-dind-rootless, dind-rootless @@ -73,39 +73,3 @@ Directory: 23.0/windows/windowsservercore-1809 Builder: classic Constraints: windowsservercore-1809 - -Tags: 20.10.24-cli, 20.10-cli, 20-cli, 20.10.24-cli-alpine3.18, 20.10.24, 20.10, 20, 20.10.24-alpine3.18 -Architectures: amd64, arm64v8 -GitCommit: 1e7a4c385eee982a26601ba6279ae6e6b52ea8d8 -Directory: 20.10/cli - -Tags: 20.10.24-dind, 20.10-dind, 20-dind, 20.10.24-dind-alpine3.18 -Architectures: amd64, arm64v8 -GitCommit: d71ed6659319c2608be2290c581787d2d4779ef2 -Directory: 20.10/dind - -Tags: 20.10.24-dind-rootless, 20.10-dind-rootless, 20-dind-rootless -Architectures: amd64, arm64v8 -GitCommit: d71ed6659319c2608be2290c581787d2d4779ef2 -Directory: 20.10/dind-rootless - -Tags: 20.10.24-git, 20.10-git, 20-git -Architectures: amd64, arm64v8 -GitCommit: f23a2bea97f6d7ec563bc316302fb8edf620ec5b -Directory: 20.10/git - -Tags: 20.10.24-windowsservercore-ltsc2022, 20.10-windowsservercore-ltsc2022, 20-windowsservercore-ltsc2022 -SharedTags: 20.10.24-windowsservercore, 20.10-windowsservercore, 20-windowsservercore -Architectures: windows-amd64 -GitCommit: 7bdd5e0d531739e1e329c939bd6d24baaffd4570 -Directory: 20.10/windows/windowsservercore-ltsc2022 -Builder: classic -Constraints: windowsservercore-ltsc2022 - -Tags: 20.10.24-windowsservercore-1809, 20.10-windowsservercore-1809, 20-windowsservercore-1809 -SharedTags: 20.10.24-windowsservercore, 20.10-windowsservercore, 20-windowsservercore -Architectures: windows-amd64 -GitCommit: 7bdd5e0d531739e1e329c939bd6d24baaffd4570 -Directory: 20.10/windows/windowsservercore-1809 -Builder: classic -Constraints: windowsservercore-1809 ```

[thaJeztah]

Thanks! I saw the tag, and was curious if that would cause havoc here (as I knew there was some automation ☺️)

[tianon]

Not havoc, just an appropriately failing auto-update that catches that case properly and avoids bumping. :smile: