[FE] Drop ApproximateIntegerLiteralTypesInReceiverPosition language feature

This feature is not needed because it is unconditionally disabled for K1
  (because of not fully correct implementation) and unconditionally enabled
  in K2 (K2 does not support old behavior)

^KT-38895

compiler/testData/ir/irText/expressions/kt42321.kt

@@ -1,5 +1,5 @@
-// !LANGUAGE: -ApproximateIntegerLiteralTypesInReceiverPosition
 // IGNORE_BACKEND_K2: JVM_IR
+// FIR status: KT-46419, ILT conversions to Byte and Short are not supported by design
 // SKIP_KT_DUMP
 // This test exists only to check that we don't accidentally break the buggy behavior of the old JVM backend in JVM IR (KT-42321).
 // Feel free to remove it as soon as there's no language version where such code is allowed (KT-38895).

compiler/testData/ir/irText/expressions/primitivesImplicitConversions.kt

@@ -1,6 +1,5 @@
-// LANGUAGE: -ApproximateIntegerLiteralTypesInReceiverPosition
 // IGNORE_BACKEND_K2: ANY
-// For reasons this test is ignored, go to KT-46419
+// FIR status: KT-46419, ILT conversions to Byte and Short are not supported by design
 
 val test1: Long = 42
 val test2: Short = 42