PY-77538 Extract PyPositionalVariadicType marker interface

that indicates types compatible with PyTypeVarTupleType: PyTypeVarTupleType and
PyUnpackedTupleType. It will allow introducing a counterpart interface for types
compatible with PyParamSpecType.

GitOrigin-RevId: 0d5c77dd21d2bc7a21b246cfbd951cdd096918e9

python/python-psi-api/src/com/jetbrains/python/psi/types/PyPositionalVariadicType.java

@@ -0,0 +1,17 @@
+// Copyright 2000-2023 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package com.jetbrains.python.psi.types;
+
+import org.jetbrains.annotations.ApiStatus;
+
+
+/**
+ * Two variants of such types described in <a href="https://peps.python.org/pep-0646/">PEP 646 – Variadic Generics</a> are
+ * TypeVarTuples and unpacked tuple types.
+ *
+ * @see PyTypeVarTupleType
+ * @see PyUnpackedTupleType
+ */
+@ApiStatus.Experimental
+public interface PyPositionalVariadicType extends PyVariadicType {
+
+}

python/python-psi-api/src/com/jetbrains/python/psi/types/PyTypeVarTupleType.java

@@ -23,5 +23,5 @@ package com.jetbrains.python.psi.types;
  * @see <a href="https://peps.python.org/pep-0646/#type-variable-tuples">PEP 646 – Variadic Generics</a>
  * @see PyUnpackedTupleType
  */
-public interface PyTypeVarTupleType extends PyTypeParameterType, PyVariadicType {
+public interface PyTypeVarTupleType extends PyTypeParameterType, PyPositionalVariadicType {
 }

python/python-psi-api/src/com/jetbrains/python/psi/types/PyUnpackedTupleType.java

@@ -17,7 +17,7 @@ import java.util.List;
  * @see <a href="https://peps.python.org/pep-0646/#unpacking-tuple-types">PEP 646 – Variadic Generics</a>
  * @see PyTypeVarTupleType
  */
-public interface PyUnpackedTupleType extends PyVariadicType {
+public interface PyUnpackedTupleType extends PyPositionalVariadicType {
   /**
    * Returns types contained inside this unpacked tuple type.
    * <p>

python/python-psi-api/src/com/jetbrains/python/psi/types/PyVariadicType.java

@@ -1,4 +1,4 @@
-// Copyright 2000-2023 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+// Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.jetbrains.python.psi.types;
 
 import com.intellij.psi.PsiElement;
@@ -15,13 +15,11 @@ import org.jetbrains.annotations.Nullable;
 import java.util.List;
 
 /**
- * A marker interface for type forms that can be "unpacked" into a series of types.
+ * A marker interface for type forms that can be "unpacked" into a collection of other types, either a nameless series,
+ * or associated with parameters of a callable type.
  * Normally, such constructs cannot be used on their own in type hints, and can appear only inside other generic types.
- * Two variants of such types described in <a href="https://peps.python.org/pep-0646/">PEP 646 – Variadic Generics</a> are 
- * TypeVarTuples and unpacked tuple types.
  *
- * @see PyTypeVarTupleType
- * @see PyUnpackedTupleType
+ * @see PyPositionalVariadicType
  */
 @ApiStatus.Experimental
 public interface PyVariadicType extends PyType {