Make "Specification Metadata" not selectable to avoid accidental highlighting?

[xfq]

https://github.com/w3c/tr-design/blob/38e0f2610dba775053ec5f5cf61bf89ff3587ade/versions-proposal.html#L17-L18 uses <details> and <summary> to hide the spec metadata by default. When expanding/collapsing it by clicking "Specification Metadata" (i.e., the <summary> element), it's easy for me to select the text in the <summary> element accidentally when expanding and collapsing the <details> element quickly (for a quick short look at the editors' name, for example), and it's a bit annoying.

Disabling the selection of the <summary> element (for example, by using user-select: none;) might be a solution for this, but I'm open to other solutions.

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See also similar discussions in w3c/i18n-drafts#123.

[fantasai]

Deferring to https://github.com/whatwg/html/issues/3191