Apply this-qualifier.md

As the feature is not actually deprecated, no changes to the spec are needed

Author: Sporarum

docs/_spec/A3-to-be-deprecated.md

@@ -0,0 +1,4 @@
+This is a simple list of feature that are not deprecated yet, but will be in the future.
+They should emit warnings or errors only when using the `-source:future` compiler flag.
+
+- [private[this] and protected[this]](../_docs/reference/dropped-features/this-qualifier.md)

docs/_spec/TODOreference/dropped-features/this-qualifier.md renamed to docs/_spec/APPLIEDreference/dropped-features/this-qualifier.md

@@ -4,7 +4,7 @@ title: "Dropped: private[this] and protected[this]"
 nightlyOf: https://docs.scala-lang.org/scala3/reference/dropped-features/this-qualifier.html
 ---
 
-The `private[this]` and `protected[this]` access modifiers are deprecated and will be phased out.
+The `private[this]` and `protected[this]` access modifiers will be deprecated and phased out.
 
 Previously, these modifiers were needed for