Update wording about javy compile in help text

[jeffcharles]

Description of the change

Updating the wording in the help text for javy compile to indicate we don't have a firm deletion date.

Why am I making this change?

We don't have a firm timeline for when we will delete the command.

Checklist

• I've updated the relevant CHANGELOG files if necessary. Changes to javy-cli and javy-plugin do not require updating CHANGELOG files.
• I've updated the relevant crate versions if necessary. Versioning policy for library crates
• I've updated documentation including crate documentation if necessary.