ci: remove android and plan9 from cross-build workflow

[mohammed90]

We added the cross-build flows to track Caddy build-ability across the known operating systems, hoping we'd be able to support them all eventually. We managed to resolve the issue for AIX by building with nobadger build tag (grrr Badger!). Plan9 build is still blocked due to dependencies. Android build requires cgo. We give up on plan9. Android has the workaround of using Termux with proot/chroot. We closed #3615.

This PR is to remove the geese we no longer are interested in supporting. I also turned the warnings into failures because now we want to know for sure if any of them fails. The final list of tested geese is:

• aix
• linux
• solaris
• illumos
• dragonfly
• freebsd
• openbsd
• windows
• darwin
• netbsd

[mholt]

This PR is to remove the geese

Amazing obscure reference to the Go standard lib.

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I'll work on that lint error...

[mholt]

Obviously the linter error is unrelated to your PR, but as I'm investigating, it's a false positive?

I run this locally in the caddytls folder:

gci list . --skip-generated -s standard -s default -s "prefix(github.com/caddyserver/caddy/v2/cmd)" -s "prefix(github.com/caddyserver/caddy)" --custom-order

And I get no output. Same result for gci diff acmeissuer.go with the same flags.

[francislavoie]

As a Canadian, I approve of the removal of geese

[mohammed90]

Obviously the linter error is unrelated to your PR, but as I'm investigating, it's a false positive?

I run this locally in the caddytls folder:

gci list . --skip-generated -s standard -s default -s "prefix(github.com/caddyserver/caddy/v2/cmd)" -s "prefix(github.com/caddyserver/caddy)" --custom-order

And I get no output. Same result for gci diff acmeissuer.go with the same flags.

I'll push the fix PR. One sec... #6270

[mholt]

Wow, thanks -- that was fast.

@francislavoie HONK 🦆

[mohammed90]

As a Canadian, I approve of the removal of geese

Can you please make it an approval GitHub recognizes? 🤣