Revert "start making Severity a type instead of str"

This reverts commit 18ca5cf.

This will allow the PR that fixes this problem to be more focused.

Author: wyattscarpenter

mypy/errors.py

@@ -21,8 +21,6 @@
 
 T = TypeVar("T")
 
-Severity = Literal["note", "warning", "error"]
-
 # Show error codes for some note-level messages (these usually appear alone
 # and not as a comment for a previous error-level message).
 SHOW_NOTE_CODES: Final = {codes.ANNOTATION_UNCHECKED, codes.DEPRECATED}
@@ -81,8 +79,8 @@ class ErrorInfo:
     # The end column number related to this error with file.
     end_column = 0  # -1 if unknown
 
-    # A set string indicating the badness of the info
-    severity: Severity
+    # Either 'error' or 'note'
+    severity = ""
 
     # The error message.
     message = ""
@@ -123,7 +121,7 @@ def __init__(
         column: int,
         end_line: int,
         end_column: int,
-        severity: Severity,
+        severity: str,
         message: str,
         code: ErrorCode | None,
         blocker: bool,
@@ -496,7 +494,7 @@ def report(
         code: ErrorCode | None = None,
         *,
         blocker: bool = False,
-        severity: Severity = "error",
+        severity: str = "error",
         file: str | None = None,
         only_once: bool = False,
         origin_span: Iterable[int] | None = None,
@@ -513,7 +511,7 @@ def report(
             message: message to report
             code: error code (defaults to misc; or None for notes), not shown for notes
             blocker: if True, don't continue analysis after this error
-            severity: a Severity like "note" or "error"
+            severity: 'error' or 'note'
             file: if non-None, override current file as context
             only_once: if True, only report this exact message once per build
             origin_span: if non-None, override current context as origin

mypy/messages.py

@@ -29,7 +29,6 @@
     ErrorWatcher,
     IterationDependentErrors,
     IterationErrorWatcher,
-    Severity,
 )
 from mypy.nodes import (
     ARG_NAMED,
@@ -234,7 +233,7 @@ def report(
         self,
         msg: str,
         context: Context | None,
-        severity: Severity,
+        severity: str,
         *,
         code: ErrorCode | None = None,
         file: str | None = None,

mypy/semanal_classprop.py

@@ -7,7 +7,7 @@
 
 from typing import Final
 
-from mypy.errors import Errors, Severity
+from mypy.errors import Errors
 from mypy.nodes import (
     IMPLICITLY_ABSTRACT,
     IS_ABSTRACT,
@@ -102,7 +102,7 @@ def calculate_class_abstract_status(typ: TypeInfo, is_stub_file: bool, errors: E
             return
         if abstract and not abstract_in_this_class:
 
-            def report(message: str, severity: Severity) -> None:
+            def report(message: str, severity: str) -> None:
                 errors.report(typ.line, typ.column, message, severity=severity)
 
             attrs = ", ".join(f'"{attr}"' for attr, _ in sorted(abstract))