No, there is no choice to select which python version is used when use builtin Python is selected. Currently the provided Python versions from Platformio are used. I have nearly finished a new pioarduino VSC plugin which is now very different to the Platformio VSC plugin. But still should be compatible too. The new VSC pioarduino extension will install the Python buillds from GitHub - astral-sh/python-build-standalone: Produce redistributable builds of Python
Can already be tested, by installing manually the extension from here pioarduino-vscode-ide/pioarduino-ide-1.1.0.vsix at pioarduino · Jason2866/pioarduino-vscode-ide · GitHub