Move docs filter logic of mount stories to the Stories block

[kasperpeulen]

Move the filtering here:

storybook/code/core/src/preview-api/modules/store/csf/prepareStory.ts

Lines 119 to 123 in db487f6

	if (mountUsed) {
	// Don't show stories where mount is used in docs.
	// As the play function is not running in docs, and when mount is used, the mounting is happening in play itself.
	tags = tags.filter((tag) => tag !== 'autodocs');
	}

To this line:

storybook/code/lib/blocks/src/blocks/Stories.tsx

Line 46 in db487f6

stories = stories.filter((story) => story.tags?.includes('autodocs'));

And revisit with @shilman if we can make it more obvious for users that those stories are filtered out.