Fix InvocationTargetException in ScalaDoc gen

This sbt command was failing with an `InvocationTargetException`:

```
+aws-s3-sdk-v2 / Compile / doc
```

...the 'doc' command is invoked during release, so we need it to work!

This is a known issue: scala/scala3#15288

See also scanamo/scanamo#1643, which looks like
it fixed the issue by downgrading to Scala 3.2.0. Weirdly, this fix did
not seem to work for me when I tried it here.

Author: rtyley

build.sbt

@@ -26,7 +26,9 @@ def awsS3WithSdkVersion(version: Int)=
       libraryDependencies ++= Seq(
         awsSdkForVersion(version),
         "com.adobe.testing" % "s3mock-testcontainers" % "3.0.1" % Test
-      )
+      ),
+      Compile / doc / sources := // https://github.com/lampepfl/dotty/issues/15288, see also https://github.com/scanamo/scanamo/pull/1643
+        { if (scalaVersion.value.startsWith("3.")) Nil else (Compile / doc / sources).value }
     )
 
 val awsSdkForVersion = Map(