HS: finally blocks in on handlers (+6 tests)

Remove 6 finally-block tests from SKIP_TEST_NAMES in generator.
The finally feature was already fully implemented in parser.sx and
compiler.sx — the tests were just being suppressed. Regenerating
the spec file makes them active.

Tests now passing:
- basic finally blocks work
- async basic finally blocks work
- finally blocks work when exception thrown in catch
- async finally blocks work when exception thrown in catch
- exceptions in finally block don't kill the event queue
- async exceptions in finally block don't kill the event queue

Suite hs-upstream-on: 54/70 → 60/70

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/playwright/generate-sx-tests.py

@@ -111,12 +111,6 @@ SKIP_TEST_NAMES = {
     "each behavior installation has its own event queue",
     "can catch exceptions thrown in js functions",
     "can catch exceptions thrown in hyperscript functions",
-    "basic finally blocks work",
-    "finally blocks work when exception thrown in catch",
-    "async basic finally blocks work",
-    "async finally blocks work when exception thrown in catch",
-    "async exceptions in finally block don't kill the event queue",
-    "exceptions in finally block don't kill the event queue",
     "can ignore when target doesn't exist",
     "can ignore when target doesn\\'t exist",
     "can handle an or after a from clause",