Remove WITH_NEW_INFERENCE directive from all tests

This directive anyway does not make test run twice with OI, and with NI
It only once run the test with specific settings (// LANGUAGE)
and ignores irrelevant (OI or NI tags)

compiler/testData/diagnostics/testsWithStdLib/contracts/smartcasts/deeplyNested.kt

@@ -1,7 +1,6 @@
 // !LANGUAGE: +AllowContractsForCustomFunctions +UseReturnsEffect
 // !USE_EXPERIMENTAL: kotlin.contracts.ExperimentalContracts
 // !DIAGNOSTICS: -INVISIBLE_REFERENCE -INVISIBLE_MEMBER
-// !WITH_NEW_INFERENCE
 
 import kotlin.contracts.*