Bootstrap 5 data attributes are data-bs-, all of them

Every JavaScript data attribute gained a bs namespace, which is a find-and-replace across every template and a silent failure if one is missed.

<!-- 4.x -->
<button data-toggle="modal" data-target="#confirm">

<!-- 5.x -->
<button data-bs-toggle="modal" data-bs-target="#confirm">

<!-- the failure: the button does nothing. no console error,
     because there is no handler looking for the old name. -->

$ grep -rn 'data-toggle|data-target|data-dismiss' resources/

The namespace exists so Bootstrap can coexist with other libraries using generic data attributes, which is a reasonable reason for an unreasonable amount of work. The silent failure is what makes it dangerous — a modal trigger that does nothing looks like a JavaScript error and produces none. Grepping for the old prefixes before and after the upgrade is the only reliable check, since no test suite covers every trigger.