Bug 1615198 [wpt PR 21773] - Remove tentative from lazy load tests, a=testonly

Bug 1615198 [wpt PR 21773] - Remove tentative from lazy load tests, a=testonly

Automatic update from web-platform-tests
Remove tentative from lazy load tests (#21773)

https://github.com/whatwg/html/pull/3752 landed, so
remove comments and tentative extension.
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wpt-commits: 283eaa796815403a3e959861f6f1e61b0d35848f
wpt-pr: 21773

--HG--
rename : testing/web-platform/tests/loading/lazyload/common.js => testing/web-platform/tests/html/semantics/embedded-content/the-img-element/common.js
rename : testing/web-platform/tests/loading/lazyload/disconnected-image-loading-lazy.tentative.html => testing/web-platform/tests/html/semantics/embedded-content/the-img-element/disconnected-image-loading-lazy.html
rename : testing/web-platform/tests/loading/lazyload/resources/image-loading-lazy-below-viewport-iframe.html => testing/web-platform/tests/html/semantics/embedded-content/the-img-element/resources/image-loading-lazy-below-viewport-iframe.html
rename : testing/web-platform/tests/loading/lazyload/resources/image-loading-lazy-in-viewport-iframe.html => testing/web-platform/tests/html/semantics/embedded-content/the-img-element/resources/image-loading-lazy-in-viewport-iframe.html
rename : testing/web-platform/tests/loading/lazyload/resources/image.png => testing/web-platform/tests/html/semantics/embedded-content/the-img-element/resources/image.png
rename : testing/web-platform/tests/loading/lazyload/resources/newwindow.html => testing/web-platform/tests/html/semantics/embedded-content/the-img-element/resources/newwindow.html
rename : testing/web-platform/tests/loading/lazyload/resources/referrer-checker-img.py => testing/web-platform/tests/html/semantics/embedded-content/the-img-element/resources/referrer-checker-img.py
rename : testing/web-platform/tests/loading/lazyload/resources/subframe.html => testing/web-platform/tests/html/semantics/embedded-content/the-img-element/resources/subframe.html