some fixes for newest conda on Windows

[schuelet]

This pull request includes several changes to the EnvironmentManager, FSKEnvironmentCreatorNodeModel, and PreferencePage classes to update dependencies, improve cross-platform compatibility, and adjust environment creation settings.

Dependency and Environment Updates:

• Updated the default Python version from 3.9 to 3.8 and modified the list of dependencies in the getPython3EnvContent method to use knime-python-base instead of individual packages.
• Added a check to exclude the "os" dependency when creating environments in the createEnvironment method.

Execution and Timeout Adjustments:

• Increased the sleep interval from 500ms to 5000ms in the waitForEnvironmentCreation method to reduce the frequency of status checks.

Cross-Platform Compatibility:

• Modified the startCondaProcess method to handle command execution differently based on the operating system, ensuring compatibility with both Windows and Unix-like systems.

Import Statements:

• Added new import statements for PythonCommand and PythonKernel in the PreferencePage class to support additional functionality.- fix conda activation in Preferences for env deletion

• added knime-python-base for EnvironmentManager
• fix for python envs in preferences not updating in the same session