Non-overlapping equality not detected inside of pattern matching case statements. #14965

Bug Report

--strict-equality does not check for non-overlapping types during a match case statement.

Case statements with Literal patterns or Constant value patterns are not checked and will not error when always-false.

The docs for --strict-equality state that these kinds of always-false comparisons are checked, though it does not mention pattern matching specifically. Otherwise this is a feature request to support checks in pattern matching case statements.

To Reproduce

Example script with various combinations of pattern matching features. All cases should error, but many don't:
https://mypy-play.net/?mypy=latest&python=3.11&flags=strict&gist=1832e8c73685a4e2ae2f84873b7573ca

Smallest reproducible sample:

match 0:
    case "str":
        pass

Expected Behavior

Always-false cases in pattern matching should be detected by Mypy with the --strict or --strict-equality flags and treated as errors.

All case statements in the the example should fail with Non-overlapping equality check ... [comparison-overlap].

Actual Behavior

Always-false case statements pass Mypy without error.

Only the cases where the matched value is assigned a name before being compared with a guard case ... if ...: are detected.

Your Environment

• Mypy version used: 1.1.1/master
• Mypy command-line flags: --strict
• Python version used: 3.11