Kapt: remove old JVM backend test data (1/2)

In this commit, .txt expectation test data files for the old JVM backend
are deleted.

 #KT-64680

plugins/kapt3/kapt3-compiler/testData/converter/enumSecondaryConstructor.txt

@@ -1,13 +0,0 @@
-public enum Foo {
-    /*public static final*/ BLA /* = new Foo() */;
-    @org.jetbrains.annotations.NotNull()
-    private final java.lang.String bla = null;
-
-    @org.jetbrains.annotations.NotNull()
-    public final java.lang.String getBla() {
-        return null;
-    }
-
-    Foo(java.lang.String bla) {
-    }
-}