PY-87191 Always provide system Python when setting up Poetry environment

- Extract PyVersionSpecifiers from Poetry-specific PoetryPythonVersion
  into python-community-openapi for reuse across subsystems
- Add PyVersionSpecifiers parameter to PythonInstallerService.installLatestPython()
  so installation respects pyproject.toml version constraints
- Pass version specifiers from getSystemPython() through to the installer
- Move pyproject.toml python-version parsing to pyproject PSI utilities
- Replace PoetryPyProjectTomlPythonVersionsService internals with PyVersionSpecifiers


(cherry picked from commit 5ef8f7cb3430826ee38cd80ab460ea4a52da919a)

IJ-MR-193218

GitOrigin-RevId: a989e2dffd5b3081db526b703f9cc6085eac96d5

python/services/system-python/src/com/intellij/python/community/services/systemPython/api.kt

@@ -19,6 +19,7 @@ import com.jetbrains.python.errorProcessing.MessageError
 import com.jetbrains.python.errorProcessing.PyError
 import com.jetbrains.python.errorProcessing.PyResult
 import com.jetbrains.python.mapError
+import com.jetbrains.python.packaging.PyVersionSpecifiers
 import com.jetbrains.python.venvReader.Directory
 import com.jetbrains.python.venvReader.VirtualEnvReader
 import org.jetbrains.annotations.ApiStatus
@@ -142,9 +143,18 @@ interface PythonInstallerService {
    * Returns Unit for now (so you should call [SystemPythonService.findSystemPythons]), but this is a subject to change.
    */
   @ApiStatus.Experimental
-  suspend fun installLatestPython(): Result<Unit, String>
+  suspend fun installLatestPython(
+    versionSpecifiers: PyVersionSpecifiers = PyVersionSpecifiers.ANY_SUPPORTED,
+  ): Result<Unit, String>
 }
 
+/**
+ * Finds the first [SystemPython] matching the given [specifiers].
+ */
+@Internal
+fun List<SystemPython>.findMatchingPython(specifiers: PyVersionSpecifiers = PyVersionSpecifiers.ANY_SUPPORTED): SystemPython? =
+  firstOrNull { specifiers.isValid(it.pythonInfo.languageLevel) }
+
 /**
  * See [createVenv]
  */

python/services/system-python/src/com/intellij/python/community/services/systemPython/systemPythonServiceImpl.kt

@@ -1,7 +1,6 @@
 // Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.intellij.python.community.services.systemPython
 
-import com.intellij.openapi.application.ApplicationManager
 import com.intellij.openapi.application.EDT
 import com.intellij.openapi.components.BaseState
 import com.intellij.openapi.components.RoamingType
@@ -31,8 +30,8 @@ import com.jetbrains.python.PythonBinary
 import com.jetbrains.python.Result
 import com.jetbrains.python.errorProcessing.getOr
 import com.jetbrains.python.getOrNull
+import com.jetbrains.python.packaging.PyVersionSpecifiers
 import com.jetbrains.python.sdk.installer.installBinary
-import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.CompletableDeferred
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
@@ -191,11 +190,12 @@ class SystemPythonServiceImpl internal constructor(
 
 
 private object LocalPythonInstaller : PythonInstallerService {
-  override suspend fun installLatestPython(): Result<Unit, String> {
-    val pythonToInstall =
-      withContext(Dispatchers.IO) {
-        PySdkToInstallManager.getAvailableVersionsToInstall().toSortedMap().values.last()
-      }
+  override suspend fun installLatestPython(versionSpecifiers: PyVersionSpecifiers): Result<Unit, String> {
+    val pythonToInstall = withContext(Dispatchers.IO) {
+      PySdkToInstallManager.getAvailableVersionsToInstall()
+        .filterKeys { versionSpecifiers.isValid(it) }
+        .maxByOrNull { it.key }?.value
+    } ?: return Result.Companion.failure("No matching Python version available for installation")
     withContext(Dispatchers.EDT) {
       installBinary(pythonToInstall, null) {
       }