[FIR] Don't perform suspend conversion for anonymous functions

^KT-58329 Fixed

compiler/testData/diagnostics/tests/inference/coerceFunctionLiteralToSuspend.fir.kt

@@ -7,7 +7,7 @@ fun fail2(c: () -> Unit) {}
 fun success1(c: suspend () -> Unit) {}
 
 fun test1() {
-    fail1(fun () {})
+    fail1(<!ARGUMENT_TYPE_MISMATCH!>fun () {}<!>)
     fun fail2(c: suspend () -> Unit) {}
     fail2(fun () {})
     fun success1(c: () -> Unit) {}
@@ -21,9 +21,9 @@ suspend fun fail4(c: () -> Unit) {}
 suspend fun success2(c: suspend () -> Unit) {}
 
 suspend fun test2() {
-    fail3(fun () {})
+    fail3(<!ARGUMENT_TYPE_MISMATCH!>fun () {}<!>)
     fun fail4(c: suspend () -> Unit) {}
     fail4(fun () {})
     fun success2(c: () -> Unit) {}
     success2(fun() {})
-}
+}