JVM IR: Remove remains of 1.2 coroutines from tests

Remove CoroutineAdapter and LANGUAGE: +ReleaseContinuation,
which are meaninless now.
Update the tests accordingly.

compiler/testData/diagnostics/testsWithStdLib/coroutines/callableReferences.kt

@@ -1,5 +1,4 @@
 // FIR_IDENTICAL
-// !LANGUAGE: +ReleaseCoroutines
 // !DIAGNOSTICS: -UNUSED_VARIABLE
 
 suspend fun foo() {}

compiler/testData/diagnostics/testsWithStdLib/coroutines/modifierFormForNonBuiltInSuspend.kt

@@ -1,5 +1,4 @@
 // FIR_IDENTICAL
-// !LANGUAGE: +ReleaseCoroutines
 // SKIP_TXT
 
 fun <R> suspend(block: suspend () -> R): suspend () -> R = block

compiler/testData/diagnostics/testsWithStdLib/coroutines/modifierFormForNonBuiltInSuspendWithAnyParameter.kt

@@ -1,5 +1,4 @@
 // FIR_IDENTICAL
-// !LANGUAGE: +ReleaseCoroutines
 // SKIP_TXT
 
 fun <R> suspend(block: R) = block

compiler/testData/diagnostics/testsWithStdLib/coroutines/nonModifierFormForBuiltIn.kt

@@ -1,5 +1,4 @@
 // FIR_IDENTICAL
-// !LANGUAGE: +ReleaseCoroutines
 // SKIP_TXT
 
 fun bar() {

compiler/testData/diagnostics/testsWithStdLib/coroutines/nonModifierFormForBuiltInRenameOnImport.fir.kt

@@ -1,4 +1,3 @@
-// !LANGUAGE: +ReleaseCoroutines
 // SKIP_TXT
 
 import kotlin.suspend as suspendLambda

compiler/testData/diagnostics/testsWithStdLib/coroutines/nonModifierFormForBuiltInRenameOnImport.kt

@@ -1,4 +1,3 @@
-// !LANGUAGE: +ReleaseCoroutines
 // SKIP_TXT
 
 import kotlin.suspend as suspendLambda

compiler/testData/diagnostics/testsWithStdLib/coroutines/release/suspend.kt

@@ -1,5 +1,4 @@
 // FIR_IDENTICAL
-// !LANGUAGE: +ReleaseCoroutines
 // SKIP_TXT
 
 suspend fun test() {

compiler/testData/diagnostics/testsWithStdLib/coroutines/restrictSuspension/outerYield_1_3.kt

@@ -1,5 +1,5 @@
 // FIR_IDENTICAL
-// !LANGUAGE: +ReleaseCoroutines +ExperimentalBuilderInference
+// !LANGUAGE: +ExperimentalBuilderInference
 // !OPT_IN: kotlin.RequiresOptIn
 // SKIP_TXT