chore: Remove files for no longer used versions

[tgodzik]

No description provided.

[tgodzik]

No need to compile or test it if we don't release for those versions.

[kitbellew]

thank you, my omission!

[agboom]

Hi @tgodzik, sorry for bumping an old PR, but could you maybe give some context as to why these old Scala versions are removed?

Recently some of our builds started breaking, indirectly because of the removal of these old versions. We use scalac-scoverage-plugin for measuring coverage, which depends on Scalameta. A few days ago this plugin removed these versions in this PR, which was causing to break our builds on Scala versions older than 2.13.10. To be fair, Scalameta still supports Scala through 2.13.8, so the Scoverage plugin seemed to go a bit further. My bad, I was looking at this PR, but main looks like it supports through 2.13.10.

The reason this happened is because we use an Ivy revision range (i.e. "[2.0.6,3)") in the scoverage plugin to make sure to support a broad enough range of Scala versions (since every patch needs a new plugin release, this reduced the maintenance burden). Keeping the old versions supported would mitigate this, but of course there may be a good reason to remove old versions, hence my question.

[kitbellew]

@agboom our release builds were taking hours and failing most often. after discussing this issue on discord, we agreed to support only the last four patches of the last two minor versions of scala2 (2.12 and 2.13) and the latest 2.11; and scala3 is not yet supported, except, of course, for parsing.

so as 2.13.13 came out, 2.13.9 was removed (see #3566).

[kitbellew]

scoverage does the same, perhaps because of us: https://github.com/scoverage/scalac-scoverage-plugin/blob/main/build.sbt#L16

[agboom]

Thanks for explaining @kitbellew, that makes sense. I should've looked on discord first 🙈
You're right, scoverage explained they follow suite: scoverage/scalac-scoverage-plugin#604 (comment)

We do try to keep our Scala versions up-to-date, but we have a lot of projects with different Scala patch versions, and a single sbt plugin that needs to support all those Scala versions. We either need to step up our Scala upgrade process or find a way to match the right scoverage plugin version to the right Scala version. But that's kind of out of scope of this discussion

[tgodzik]

We generate a list of supported versions here https://github.com/scalameta/metals/blob/main/project/SemanticDbSupport.scala#L3

So we can match semanticdb version to Scala version. Might be useful for you.