[FIR LT] Unmute some stepping and local variable tests

Corresponding tests were fixed together with #KT-56982, #KT-56913,
#KT-56926

compiler/testData/debug/localVariables/receiverMangling/capturedThisField.kt

@@ -1,5 +1,3 @@
-// IGNORE_BACKEND_K2_LIGHT_TREE: JVM_IR
-//   Reason: KT-56755
 // FILE: test.kt
 class Foo {
     inner class Bar {
@@ -12,18 +10,18 @@ fun box() {
 }
 
 // EXPECTATIONS JVM JVM_IR
-// test.kt:10 box:
-// test.kt:4 <init>:
-// test.kt:10 box:
-// test.kt:11 box: x:Foo=Foo
-// test.kt:5 <init>:
-// test.kt:11 box: x:Foo=Foo
-// test.kt:12 box: x:Foo=Foo
+// test.kt:8 box:
+// test.kt:2 <init>:
+// test.kt:8 box:
+// test.kt:9 box: x:Foo=Foo
+// test.kt:3 <init>:
+// test.kt:9 box: x:Foo=Foo
+// test.kt:10 box: x:Foo=Foo
 
 // EXPECTATIONS JS_IR
-// test.kt:10 box:
-// test.kt:4 <init>:
-// test.kt:11 box: x=Foo
-// test.kt:5 <init>:
-// test.kt:5 <init>:
-// test.kt:12 box: x=Foo
+// test.kt:8 box:
+// test.kt:2 <init>:
+// test.kt:9 box: x=Foo
+// test.kt:3 <init>:
+// test.kt:3 <init>:
+// test.kt:10 box: x=Foo