Stabilize reflect flag JavaAnnotation (#19267)

Flag added in #16260

Author: smarter

library/src/scala/quoted/Quotes.scala

@@ -4516,7 +4516,7 @@ trait Quotes { self: runtime.QuoteUnpickler & runtime.QuoteMatching =>
       def JavaStatic: Flags
 
       /** Is this an annotation defined in Java */
-      @experimental def JavaAnnotation: Flags
+      def JavaAnnotation: Flags
 
       /** Is this symbol `lazy` */
       def Lazy: Flags

tests/run-tasty-inspector/stdlibExperimentalDefinitions.scala

@@ -72,7 +72,6 @@ val experimentalDefinitionInLibrary = Set(
   "scala.quoted.Quotes.reflectModule.SymbolMethods.paramVariance",
   // Can be stabilized in 3.4.0 (unsure) or later
   "scala.quoted.Quotes.reflectModule.CompilationInfoModule.XmacroSettings",
-  "scala.quoted.Quotes.reflectModule.FlagsModule.JavaAnnotation",
   // Cant be stabilized yet.
   // Need newClass variant that can add constructor parameters.
   // Need experimental annotation macros to check that design works.