Use / for pos-only params (#1799)

* Use `/` for pos-only params

* Update pipe.pyi

* Update pipe.pyi

* Update pipe.pyi

* Update pipe.pyi

Author: sobolevn

returns/_internal/pipeline/pipe.pyi

@@ -56,55 +56,60 @@ class _Pipe(Generic[
     See docs on ``pipe`` feature in ``mypy`` plugin.
     """
 
-    def __init__(self, __functions: tuple[
-        _PipelineStepType1,
-        _PipelineStepType2,
-        _PipelineStepType3,
-        _PipelineStepType4,
-        _PipelineStepType5,
-        _PipelineStepType6,
-        _PipelineStepType7,
-        _PipelineStepType8,
-        _PipelineStepType9,
-        _PipelineStepType10,
-        _PipelineStepType11,
-        _PipelineStepType12,
-        _PipelineStepType13,
-        _PipelineStepType14,
-        _PipelineStepType15,
-        _PipelineStepType16,
-        _PipelineStepType17,
-        _PipelineStepType18,
-        _PipelineStepType19,
-        _PipelineStepType20,
-    ]) -> None:
+    def __init__(  # noqa: WPS451
+        self,
+        functions: tuple[
+            _PipelineStepType1,
+            _PipelineStepType2,
+            _PipelineStepType3,
+            _PipelineStepType4,
+            _PipelineStepType5,
+            _PipelineStepType6,
+            _PipelineStepType7,
+            _PipelineStepType8,
+            _PipelineStepType9,
+            _PipelineStepType10,
+            _PipelineStepType11,
+            _PipelineStepType12,
+            _PipelineStepType13,
+            _PipelineStepType14,
+            _PipelineStepType15,
+            _PipelineStepType16,
+            _PipelineStepType17,
+            _PipelineStepType18,
+            _PipelineStepType19,
+            _PipelineStepType20,
+        ],
+        /,
+    ) -> None:
         ...
 
     def __call__(self, instance: _InstanceType) -> _ReturnType:
         ...
 
 
-def pipe(
-    __function1: _PipelineStepType1,
-    __function2: _PipelineStepType2 = ...,
-    __function3: _PipelineStepType3 = ...,
-    __function4: _PipelineStepType4 = ...,
-    __function5: _PipelineStepType5 = ...,
-    __function6: _PipelineStepType6 = ...,
-    __function7: _PipelineStepType7 = ...,
-    __function8: _PipelineStepType8 = ...,
-    __function9: _PipelineStepType9 = ...,
-    __function10: _PipelineStepType10 = ...,
-    __function11: _PipelineStepType11 = ...,
-    __function12: _PipelineStepType12 = ...,
-    __function13: _PipelineStepType13 = ...,
-    __function14: _PipelineStepType14 = ...,
-    __function15: _PipelineStepType15 = ...,
-    __function16: _PipelineStepType16 = ...,
-    __function17: _PipelineStepType17 = ...,
-    __function18: _PipelineStepType18 = ...,
-    __function19: _PipelineStepType19 = ...,
-    __function20: _PipelineStepType20 = ...,
+def pipe(  # noqa: WPS451
+    function1: _PipelineStepType1,
+    function2: _PipelineStepType2 = ...,
+    function3: _PipelineStepType3 = ...,
+    function4: _PipelineStepType4 = ...,
+    function5: _PipelineStepType5 = ...,
+    function6: _PipelineStepType6 = ...,
+    function7: _PipelineStepType7 = ...,
+    function8: _PipelineStepType8 = ...,
+    function9: _PipelineStepType9 = ...,
+    function10: _PipelineStepType10 = ...,
+    function11: _PipelineStepType11 = ...,
+    function12: _PipelineStepType12 = ...,
+    function13: _PipelineStepType13 = ...,
+    function14: _PipelineStepType14 = ...,
+    function15: _PipelineStepType15 = ...,
+    function16: _PipelineStepType16 = ...,
+    function17: _PipelineStepType17 = ...,
+    function18: _PipelineStepType18 = ...,
+    function19: _PipelineStepType19 = ...,
+    function20: _PipelineStepType20 = ...,
+    /,
 ) -> _Pipe[
     _InstanceType,
     _ReturnType,