[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/src/parser/mod.rs

@@ -1060,10 +1060,10 @@ impl RecoveryContextKind {
                 None => {
                     // test_ok match_sequence_pattern_terminator
                     // match subject:
-                    //     case a: ...
                     //     case a if x: ...
                     //     case a, b: ...
                     //     case a, b if x: ...
+                    //     case a: ...
                     matches!(p.current_token_kind(), TokenKind::Colon | TokenKind::If)
                         .then_some(ListTerminatorKind::Regular)
                 }