Fixes #49368

This PR updates the hover text for overloaded function signatures: it prevents the @deprecated JSDoc tag from being passed on to other signatures of the same overloaded function (see the linked issue for examples).
This is relevant because it enables the author of the module to deprecate only certain signatures. This behaviour also now aligns the hover text with the existing behaviour of the VS Code "strikethrough" styling.

Please verify that:

• There is an associated issue in the Backlog milestone (required)
• Code is up-to-date with the main branch
• You've successfully run gulp runtests locally
• [?] There are new or updated unit tests validating the change
  • I've added fourslash tests