Update README to reflect that `exportRequirementsWithUrls` option is for Poetry projects only

[chang-annie]

The exportRequirementsWithUrls adds the --without-urls option the the export command. However, this is only available in Poetry at this moment. We should update the README to reflect that this configuration should be applied for Poetry projects only.

Definition of Done

• Update exportRequirementsWithUrls configuration section of README to say that it's Poetry specific only

Test Steps/Strategy

• Confirm exportRequirementsWithUrls configuration section of README states that the option is Available for Poetry projects only.

[chang-annie]

After investigation, we have discovered the following:

• The poetry-plugin-export is no longer being installed by default with Poetry v2.0.0+. However, for Poetry projects, Habushu brings in this plugin through the PyenvAndPoetrySetup step when we're installing the poetry-monorepo-dependency-plugin
• The --without-urls option for the poetry export command has not been deprecated and is still valid. This was confirmed by installing the poetry-plugin-export and running the help command. It was also tested by running using the option and confirming that the source URLs are included/omitted based on the setting

Based on the above and the fact that the --without-urls option is not available for UV export at this time, this ticket's objective has been updated to add a note to the documentation specifying that the exportRequirementsWithUrls configuration is for Poetry projects only.

[chang-annie]

DOD and OTS completed with @aaron-gary

[d-ryan-ashcraft]

Test Results - ✅ PASSED