[syntax-errors] Irrefutable case pattern before final case (#16905)

Summary
--

Detects irrefutable `match` cases before the final case using a modified
version
of the existing `Pattern::is_irrefutable` method from the AST crate. The
modified method helps to retrieve a more precise diagnostic range to
match what
Python 3.13 shows in the REPL.

Test Plan
--

New inline tests, as well as some updates to existing tests that had
irrefutable
patterns before the last block.

crates/ruff_python_parser/resources/inline/err/irrefutable_case_pattern.py

@@ -0,0 +1,12 @@
+match x:
+    case var: ...  # capture pattern
+    case 2: ...
+match x:
+    case _: ...
+    case 2: ...    # wildcard pattern
+match x:
+    case var1 as var2: ...  # as pattern with irrefutable left-hand side
+    case 2: ...
+match x:
+    case enum.variant | var: ...  # or pattern with irrefutable part
+    case 2: ...