PY-80049: Check Python2 version correctly.

We execute `--version` to find python version.
Since 3.4 Python uses stdout for output, but before that it used stderr.

We now check both: stdout and stderr.

GitOrigin-RevId: ca9059b71cabbd1a94e26523192cdf9eeb8c1eb1

python/setup-test-environment/src/com/intellij/python/community/testFramework/testEnv/PythonType.kt

@@ -41,7 +41,6 @@ abstract class PythonType<T : Any>(private val tag: @NonNls String) {
           ?: error("Can't get language level for $flavor , $binary")
         }
         .sortedByDescending { (_, languageLevel) -> languageLevel }
-        .filter { (_, languageLevel) -> languageLevel.isPy3K }
         .map { (path, _) -> path }
     }
     return pythons.asFlow()

python/setup-test-environment/src/com/intellij/python/community/testFramework/testEnv/TypeVanillaPython3.kt

@@ -11,7 +11,7 @@ import com.jetbrains.python.PyNames
 import com.jetbrains.python.PythonBinary
 import java.nio.file.Path
 
-data object TypeVanillaPython3 : PythonType<PythonBinary>("python3") {
+open class TypeVanillaPython(tag: String) : PythonType<PythonBinary>(tag) {
   override suspend fun createSdkFor(python: PythonBinary): Sdk = createSdk(python)
 
   fun createSdk(python: PythonBinary): Sdk =
@@ -27,4 +27,6 @@ data object TypeVanillaPython3 : PythonType<PythonBinary>("python3") {
       Disposer.dispose(disposable)
     })
   }
-}
+}
+
+object TypeVanillaPython3 : TypeVanillaPython("python3")