fix(next/image): add `?dpl` query string for local images (without static import) (#86485)
In a previous PR https://github.com/vercel/next.js/pull/73184 the `?dpl`
query string was added to local images from static imports but not to
images without the static import.
This was a subtle change based on malte's PR review comment here:
https://github.com/vercel/next.js/pull/73184#issuecomment-2499126751
However, I can't think of reason why we should differentiate these two
since they are both related to the current deployment (as opposed to
remote images which live outside the deployment).
Furthermore, this string matching is causing microfrontends to fail to
add the `?dpl` because they have a path prefix and thus fail skew
protection.
So this PR fixes both problems by loosening the string matching to look
for src images that start with `/`.