CICD: Auto-generate GoReleaser provider regexp

[cafferata]

The Provider-specific changes regexp in .goreleaser.yml is a hardcoded list of provider names used to group changelog entries. When a new provider is added, this regexp must be manually updated, which is easy to forget.

- title: 'Provider-specific changes:'
  regexp: "(?i)((adguardhome|akamaiedgedns|alidns|...|vultr).*:)+.*"

Auto-generating this list from the registered provider constants would solve that, but introduces a question about historical aliases. In #4072 (comment) @TomOnTime (@tlimoncelli) noted that both CLOUDFLAREAPI and the common shorthand CLOUDFLARE should be accepted. With auto-generation only CLOUDFLAREAPI would appear, since that's the registered constant. The same applies to other historical aliases like HEXONET (now CNR), GANDI (now GANDI_V5), NSONE (now NS1), etc.

How should we handle these?

[TomOnTime]

How should we handle these?

Excellent question! For now, let's just hard-code adding the aliases. In the future, I plan on adding a way for providers to list aliases (See a prototype #3941)

[cafferata]

Sounds good. Since this list will be auto-generated by go generate, would you prefer the aliases to live in the generator itself, or somewhere more central like a map in pkg/providers/?

Asking because a hard-coded list in .goreleaser.yml would be overwritten once the generator is in place.

[TomOnTime]

Sounds good. Since this list will be auto-generated by go generate, would you prefer the aliases to live in the generator itself, or somewhere more central like a map in pkg/providers/?

Whatever is easiest.