Post editor layout issues when creating a synced pattern

[bgardner]

Description

I am trying to create a synced pattern from a group that has full width layout. After I create the pattern, the contents of the group are reduced to the regular content width as a result of this css:

.editor-styles-wrapper .block-editor-block-list__layout.is-root-container > :where(:not(.alignleft):not(.alignright):not(.alignfull)) {
    max-width: 640px;
    margin-left: auto !important;
    margin-right: auto !important;
}

Step-by-step reproduction instructions

1. Create a group and apply full width layout.
2. Convert group to a synced pattern.
3. See issue.

Screenshots, screen recording, code snippet

Screen.Recording.2023-08-09.at.8.40.46.PM.mov

Environment info

WordPress 6.3, Gutenberg 16.4.

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

[bgardner]

Worth noting the issue only exists on the back end, as the front end displays properly at full width.

[bgardner]

Confirmed issue with TT3 as well:

Screen.Recording.2023-08-09.at.8.53.43.PM.mov

[bgardner]

Closing b/c dupe: #8288