Bump zio-sbt-ci/zio-sbt-website off the SNAPSHOT once zio-sbt cuts a release

Context

#632 pins zio-sbt-ci/zio-sbt-website to 0.7.2+1-4854ac94-SNAPSHOT in project/plugins.sbt, resolved from Sonatype's Central Portal snapshots repo. That snapshot carries the sbt 2.x/Scala 3 dual cross-build support from zio/zio-sbt#760, which is required for this project to build at all under sbt.version = 2.0.7 - it hasn't shipped in a numbered zio-sbt release yet (latest at the time was v0.7.2).

Why this needs following up

Sonatype does not retain snapshot artifacts indefinitely. Once the snapshot backing this version is cleaned up, project/plugins.sbt resolution breaks and nobody can build this project until it's re-pinned.

What to do

Once zio-sbt publishes a numbered release containing #760 (e.g. v0.7.3 or later):

1. Bump project/plugins.sbt:

   addSbtPlugin("dev.zio" % "zio-sbt-website" % "<new version>")
   addSbtPlugin("dev.zio" % "zio-sbt-ci"      % "<new version>")
   

2. Remove the now-unneeded snapshot resolver:

   resolvers += "Central Sonatype Snapshots" at "https://central.sonatype.com/repository/maven-snapshots/"
   

3. Run sbt ciGenerateGithubWorkflow and commit any resulting .github/workflows/ci.yml diff.
4. Run sbt lint (includes ciCheckGithubWorkflow) and sbt +publishLocal to confirm everything still resolves and builds.

Reference

• zio/zio-cli#632 - introduced the snapshot pin
• zio/zio-sbt#760 - the sbt2/Scala3 cross-build support this snapshot carries

Wait for a numbered zio-sbt release containing zio-sbt#760, then update the two plugin versions and remove the snapshot resolver in project/plugins.sbt. Run sbt ciGenerateGithubWorkflow and inspect any .github/workflows/ci.yml changes, then run sbt lint and sbt +publishLocal. Done means the project resolves and builds without the snapshot repository.