I shouldn’t be able to share the 'Delete node' page

Problem/Motivation

When I'm deleting a public page, I should't be able to share it via the Share this page block.

Steps to reproduce

1. Enable the Social Sharing module
1. Create a new 'Basic page'
2. Set visibility to Public
3. Try to delete the newly created page, on the confirmation page the "Share this page" block will still be visible.

Proposed resolution

Add the 'entity.node.delete_form' route to the excluded routes in the Social Sharing module.

Remaining tasks

None

User interface changes

The "Share this page" block will no longer be visible, when deleting a public page.

API changes

None

Data model changes

None