[Bug]: `BrandImage` resizes itself in dark theme when resizing sidebar

[Maya Buser De]

Describe the bug

When switching to the Storybook dark theme, the BrandImage resizes itself when changing the width of the sidebar. The same problem seems to have been addressed for the light theme in this issue: #24702.

Depending on the width of the sidebar, the logos might be different sizes when switching between themes.

I think the dark theme should behave like the light theme.

Screen.Recording.2024-06-10.at.3.04.54.PM.mov

Reproduction link

N/A

Reproduction steps

No response

System

Storybook Environment Info:

  System:
    OS: macOS 14.5
    CPU: (10) arm64 Apple M1 Pro
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 18.7.0 - ~/.nvm/versions/node/v18.7.0/bin/node
    Yarn: 1.22.19 - ~/.nvm/versions/node/v18.7.0/bin/yarn
    npm: 8.15.0 - ~/.nvm/versions/node/v18.7.0/bin/npm
    pnpm: 8.3.1 - ~/.nvm/versions/node/v18.7.0/bin/pnpm <----- active
  Browsers:
    Chrome: 125.0.6422.142
    Edge: 125.0.2535.92
    Safari: 17.5
  npmPackages:
    @storybook/addon-a11y: 8.0.9 => 8.0.9 
    @storybook/addon-actions: 8.0.9 => 8.0.9 
    @storybook/addon-essentials: 8.0.9 => 8.0.9 
    @storybook/blocks: 8.0.9 => 8.0.9 
    @storybook/theming: 8.0.9 => 8.0.9 
    @storybook/web-components: 8.0.9 => 8.0.9 
    @storybook/web-components-vite: 8.0.9 => 8.0.9 
    chromatic: 5.8.3 => 5.8.3 
    storybook: 8.0.9 => 8.0.9 
    storybook-dark-mode: 4.0.1 => 4.0.1

Additional context

No response