RFC: stop supporting GoLang 1.20

[YOU54F]

In order to update our grpc dependency, we would need to drop support for the now EOL 1.20 which ended 5 months and 3 weeks ago (06 Feb 2024)

See blocked PR and comment.

#444 (comment)

Would this impact any existing pact-go users?

Do you have to support golang applications, outside of golangs supported release cycle?

Go's EOL dates - https://endoflife.date/go

[mefellows]

Tricky. There's no reason Pact Go won't work on these older versions, if not for these example-related dependencies.

We could skip tests on Go versions older than X but I think that just gets messy.

The policy has always been to support the current supported versions of languages, so I'm comfortable with dropping support for 1.20.

[mefellows]

Merging the related PR, and accepting this RFC.