Akuli and srittau: Remove Python 2 branches from Python 3 stubs (#5461)

* run script and do some manual changes (Akuli)

* do the whole thing manually (srittau)

* merge changes (Akuli)

Co-authored-by: Sebastian Rittau <srittau@rittau.biz>

stdlib/sched.pyi

@@ -1,4 +1,3 @@
-import sys
 from typing import Any, Callable, Dict, List, NamedTuple, Optional, Text, Tuple
 
 class Event(NamedTuple):
@@ -9,30 +8,24 @@ class Event(NamedTuple):
     kwargs: Dict[Text, Any]
 
 class scheduler:
-    if sys.version_info >= (3, 3):
-        def __init__(self, timefunc: Callable[[], float] = ..., delayfunc: Callable[[float], None] = ...) -> None: ...
-        def enterabs(
-            self,
-            time: float,
-            priority: Any,
-            action: Callable[..., Any],
-            argument: Tuple[Any, ...] = ...,
-            kwargs: Dict[str, Any] = ...,
-        ) -> Event: ...
-        def enter(
-            self,
-            delay: float,
-            priority: Any,
-            action: Callable[..., Any],
-            argument: Tuple[Any, ...] = ...,
-            kwargs: Dict[str, Any] = ...,
-        ) -> Event: ...
-        def run(self, blocking: bool = ...) -> Optional[float]: ...
-    else:
-        def __init__(self, timefunc: Callable[[], float], delayfunc: Callable[[float], None]) -> None: ...
-        def enterabs(self, time: float, priority: Any, action: Callable[..., Any], argument: Tuple[Any, ...]) -> Event: ...
-        def enter(self, delay: float, priority: Any, action: Callable[..., Any], argument: Tuple[Any, ...]) -> Event: ...
-        def run(self) -> None: ...
+    def __init__(self, timefunc: Callable[[], float] = ..., delayfunc: Callable[[float], None] = ...) -> None: ...
+    def enterabs(
+        self,
+        time: float,
+        priority: Any,
+        action: Callable[..., Any],
+        argument: Tuple[Any, ...] = ...,
+        kwargs: Dict[str, Any] = ...,
+    ) -> Event: ...
+    def enter(
+        self,
+        delay: float,
+        priority: Any,
+        action: Callable[..., Any],
+        argument: Tuple[Any, ...] = ...,
+        kwargs: Dict[str, Any] = ...,
+    ) -> Event: ...
+    def run(self, blocking: bool = ...) -> Optional[float]: ...
     def cancel(self, event: Event) -> None: ...
     def empty(self) -> bool: ...
     @property