Docs tab (@storybook/addon-docs): canvas' content copying doesn't work

[jphawk]

Describe the bug
Nothing can be copied from the canvas preview (.sbdocs-preview container) in the Docs tab (@storybook/addon-docs). The bug disappears if Storybook settings in preview.js has inlineStories: false in docs parameters. The content of the canvas can be copied.

To Reproduce

1. Navigate to Docs tab in a Story
2. Copy some text from there, try to paste it to somewhere

System
System:
OS: macOS 12.4
CPU: (12) x64 Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz
Binaries:
Node: 14.17.3 - /usr/local/bin/node
npm: 8.12.0
Browsers:
Chrome: 102.0.5005.61
Edge: 102.0.1245.33
Firefox: 95.0
Safari: 15.5
npmPackages:
@storybook/addon-a11y: 6.4.22 => 6.4.22
@storybook/addon-docs: 6.5.3 => 6.5.3
@storybook/addon-essentials: 6.4.22 => 6.4.22
@storybook/addon-jest: 6.4.22 => 6.4.22
@storybook/addon-storysource: 6.4.22 => 6.4.22
@storybook/addons: 6.4.22 => 6.4.22
@storybook/builder-webpack5: 6.4.22 => 6.4.22
@storybook/manager-webpack5: 6.4.22 => 6.4.22
@storybook/preset-create-react-app: 4.1.0 => 4.1.0
@storybook/react: 6.4.22 => 6.4.22
@storybook/theming: 6.4.22 => 6.4.22

[pocka]

Duplicate of #18611