Element lang correct: remove inapplicable examples

[WilcoFiers]

This PR removes inapplicable examples from the HTML element language subtag matches language rule, which according to Element with lang attribute has valid language tag should be considered failures of 3.1.2.

Two of those examples are literal failed examples of the lang attribute valid rule.

AGWG has agreed that those examples are failures of SC 3.1.2, so we can't use them as inapplicable examples here. I'm open to suggestions for alternative examples that would not fail other rules.

Need for Call for Review: 1 week

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[Jym77]

I agree that we cannot have these Inapplicable examples, and given the structure of the rules, we are likely in a case similar to HTML page lang attribute has valid language tag not having an "empty lang" Inapplicable example because it would fail the SC according to the companion HTML page has lang attribute.

[Jym77]

Two of those examples are literal failed examples of the lang attribute valid rule.

AGWG has agreed that those examples are failures of SC 3.1.2, so we can't use them as inapplicable examples here. I'm open to suggestions for alternative examples that would not fail other rules.

Maybe we should just add "Related rules" links between these two rules, the same way we did for the three "document lang" rules 🤔

[daniel-montalvo]

Tests complain that we are defining "language subtag registry" but we are not using it as we have removed the examples where we used it.

In any case, approving.