Ensure data-bs-toggle is present in the BS3 tabset compatibility shims

[gadenbuie]

As we noticed in rstudio/flexdashboard#421, newer version of Bootstrap may require the data-bs-toggle in places where data-toggle was previously sufficient. In theory, we could handle this in the tabset compatibility shims by ensuring that data-toggle is copied to data-bs-toggle if the latter isn't present.

bslib/inst/bs3compat/js/bs3compat.js

Lines 27 to 31 in 9c043a7

	var SELECTOR = '[data-toggle="tab"], [data-toggle="pill"], [data-bs-toggle="tab"], [data-bs-toggle="pill"]';
	$(document).on(EVENT_KEY, SELECTOR, function(event) {
	event.preventDefault();
	$(this).tab("show");
	});