Disable -Xsource:3 in docs due to mdoc failures:

```
error: basics.md:97 (mdoc generated code) could not find implicit value for parameter t: pprint.TPrint[zio.ZIO[zio.Has[zio.console.Console.Service],Throwable,β$0$]]
val injector: Injector[RIO[Console, _]] = Injector[RIO[Console, _]](); $doc.binder(injector, 2, 4, 2, 12)
                                                                                  ^

error: basics.md:109 (mdoc generated code) could not find implicit value for parameter t: pprint.TPrint[zio.ZIO[zio.Has[zio.console.Console.Service],Throwable,β$0$]]
val resource = injector.produce(plan); $doc.binder(resource, 4, 4, 4, 12)
                                                  ^

error: basics.md:1359 (mdoc generated code) could not find implicit value for parameter t: pprint.TPrint[zio.ZIO[zio.Has[zio.console.Console.Service],Throwable,β$9$]]
val res51 = chooseInterpreters(true); $doc.binder(res51, 26, 0, 26, 24)
```

Author: neko-kai

build.sbt

@@ -3217,6 +3217,7 @@ lazy val `microsite` = project.in(file("doc/microsite"))
       case (_, _) => Seq.empty
     } },
     scalacOptions -= "-Wconf:any:error",
+    scalacOptions -= "-Xsource:3",
     coverageEnabled := false,
     publish / skip := true,
     DocKeys.prefix := {if (isSnapshot.value) {

project/Deps.sc

@@ -582,6 +582,7 @@ object Izumi {
         depends = all.flatMap(_.artifacts).map(_.name in Scope.Compile.all).distinct,
         settings = Seq(
           "scalacOptions" -= "-Wconf:any:error",
+          "scalacOptions" -= "-Xsource:3",
           "coverageEnabled" := false,
           "skip" in SettingScope.Raw("publish") := true,
           "DocKeys.prefix" :=