Revert "don't require publishTo specified if publishArtifact is `false`"

This reverts commit 4668faff7c.
Ref https://github.com/sbt/sbt/pull/3760
Ref https://github.com/sbt/sbt/pull/4931

main/src/main/scala/sbt/Defaults.scala

@@ -2338,10 +2338,8 @@ object Classpaths {
         if (isSnapshot.value) "integration" else "release",
         ivyConfigurations.value.map(c => ConfigRef(c.name)).toVector,
         packagedArtifacts.in(publish).value.toVector,
-        checksums.in(publish).value.toVector, { //resolvername: not required if publishTo is false
+        checksums.in(publish).value.toVector,
-          val publishToOption = publishTo.value
+        getPublishTo(publishTo.value).name,
-          if (publishArtifact.value) getPublishTo(publishToOption).name else "local"
-        },
         ivyLoggingLevel.value,
         isSnapshot.value
       )

notes/1.2.0/publishTo-not-required-if-not-publishing.md

@@ -1,12 +0,0 @@
-
-[@mpollmeier]: https://github.com/mpollmeier
-
-[#3760]: https://github.com/sbt/sbt/pull/3760
-
-### Fixes with compatibility implications
-
-### Improvements
-
-### Bug fixes
-
-- Remove requirement on `publishTo` if `publishArtifact` is false. [#3760][] by [@mpollmeier][]

sbt/src/sbt-test/project/no-publish/build.sbt

@@ -1,3 +0,0 @@
-// this is supposed to do nothing, and more importantly: not fail
-// https://github.com/sbt/sbt/pull/3760
-publishArtifact := false

sbt/src/sbt-test/project/no-publish/test

@@ -1 +0,0 @@
-> publish