Block toolbar overlaps the first block when creating a pattern or template part

[talldan]

Step-by-step reproduction instructions

Site editor

1. Select Appearance > Edit Site
2. Go to the Patterns page
3. Click 'Add New Pattern' and choose a pattern or template part
4. Name the pattern or template part and create it
5. Type some text in the first block, then move your mouse and observe that the toolbar overlaps the block, making editing difficult

Post editor

1. Add a paragraph and type some text
2. From the block options menu select 'Create Pattern'
3. Name and create the pattern
4. When the pattern is inserted select the 'Edit Original' option form the block toolbar
5. Select the first block and observe that the toolbar overlaps the paragraph

Screenshots, screen recording, code snippet

Environment info

• WordPress and Gutenberg trunk
• Brave browser

Please confirm that you have searched existing issues in the repo.

Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

Yes

[talldan]

A possible fix here is to increase the padding around the canvas, but it looks unusual in practice:

When there's more content, the toolbar flips below the first block, so I think it should also do this when there's one block:

[talldan]

Fixed by #64143