[FIR2IR] Unconditionally disable linkViaSignatures on JVM

It was an experimental compilation mode that we don't need anymore.

KT-64809

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/arguments/K2JVMCompilerArguments.kt

@@ -785,7 +785,9 @@ See KT-45671 for more details."""
     @Argument(
         value = "-Xlink-via-signatures",
         description = """Link JVM IR symbols via signatures instead of descriptors.
-This mode is slower, but it can be useful for troubleshooting problems with the JVM IR backend."""
+This mode is slower, but it can be useful for troubleshooting problems with the JVM IR backend.
+This option is deprecated and will be deleted in future versions.
+It has no effect when -language-version is 2.0 or higher."""
     )
     var linkViaSignatures = false
         set(value) {