Create simplejson.errors (#6492)

stubs/simplejson/simplejson/errors.pyi

@@ -0,0 +1,16 @@
+__all__ = ["JSONDecodeError"]
+
+def linecol(doc: str, pos: int) -> tuple[int, int]: ...
+def errmsg(msg: str, doc: str, pos: int, end: int | None = ...) -> str: ...
+
+class JSONDecodeError(ValueError):
+    msg: str
+    doc: str
+    pos: int
+    end: int | None
+    lineno: int
+    colno: int
+    endlineno: int | None
+    endcolno: int | None
+    def __init__(self, msg: str, doc: str, pos: int, end: int | None = ...) -> None: ...
+    def __reduce__(self) -> tuple[JSONDecodeError, tuple[str, str, int, int | None]]: ...