kotlin tests: sync generated-throws.kt source between test-kotlin1 and test-kotlin2

Remove the K1-only comment '// This doesn't generate a throw statement in
Kotlin 1 mode' from test-kotlin1/library-tests/generated-throws/generated-throws.kt
so the source files are byte-identical between the two suites.

The expected outputs still legitimately differ: in K2 mode the compiler generates
an implicit throw NoWhenBranchMatchedException for the exhaustive sealed-class when
expression, but the K1 frontend does not emit this node. This is a mode-specific
behaviour difference that cannot be bridged by an extractor change.

Both tests continue to pass:
- test-kotlin1 (kotlinc 2.3.20 / -language 1.9): 0 throw results (unchanged)
- test-kotlin2 (kotlinc 2.4.0 / -language 2.0): 1 throw result (unchanged)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

java/ql/test-kotlin1/library-tests/generated-throws/generated-throws.kt

@@ -4,7 +4,6 @@ interface Bar: Foo {}
 interface Baz: Foo {}
 
 private fun someFun(v: Foo) {
-    // This doesn't generate a throw statement in Kotlin 1 mode
     when (v) {
         is Bar -> {}
         is Baz -> {}