Description

If i have a paragraph with the block editing mode set to disabled it shouldnt be able to be merged with another block. Currently what happens is that it merges both blocks into the disabled block. What should happen is that merging is prevented.

Step-by-step reproduction instructions

1. Create a post
2. Add two paragraphs
3. Open console run the following wp.data.dispatch('core/block-editor').setBlockEditingMode( wp.data.select('core/block-editor').getBlocks()[0].clientId, 'disabled')
4. in the second paragraph put the cursor to the front of the block
5. hit backspace
6. see that the blocks have been merged when they shouldn't have been.

Screenshots, screen recording, code snippet

Environment info

• Tested on WP6.6, 6.7 and 6.8
• Browser latest chrome (i imagine it would occur on others)
• Device Macbook Pro

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

Please confirm which theme type you used for testing.

• Block
• Classic
• Hybrid (e.g. classic with theme.json)
• Not sure