Revert "K2/Java: add private enum constructor for MPP matching"

Review: https://jetbrains.team/p/kt/reviews/13368/timeline

This reverts commit 2cea2b9098.

Motivation:
KT-62961 was fixed independently by two different commits:
- ac3d8ad3ac
- 2cea2b9098

If possible, it's better not to introduce implicit declarations.
That's why it was agreed to keep
ac3d8ad3ac and revert
2cea2b9098

compiler/testData/loadJava/compiledJava/annotations/NestedEnumArgument.fir.txt

@@ -18,7 +18,5 @@ public open class NestedEnumArgument : R|kotlin/Any| {
         public final static val entries: R|kotlin/enums/EnumEntries<test/NestedEnumArgument.E>|
             public get(): R|kotlin/enums/EnumEntries<test/NestedEnumArgument.E>|
 
-        private constructor(): R|test/NestedEnumArgument.E|
-
     }
 }