Re-enable admin View Transitions in Chromium after Chromium crash is resolved

Let's re-enable admin View Transitions in Chromium after Chromium crash is resolved:

https://issues.chromium.org/issues/530704642

For context, playground disabled admin View Transitions in Chromium-based browsers in https://github.com/WordPress/wordpress-playground/issues/3845 because Chromium crashed during the transition.

Follow-up to https://github.com/WordPress/wordpress-playground/issues/3845 and PR https://github.com/WordPress/wordpress-playground/pull/3886.

What needs to happen

Once the Chromium bug is fixed and available in stable Chrome/Edge:

• Verify the crash no longer reproduces in a stable Chromium-based browser.
• Remove the Chromium-only admin View Transitions workaround from packages/playground/remote/src/lib/playground-worker-endpoint.ts.
• Confirm Playground’s fallback View Transitions and WordPress Core’s wp-view-transitions-admin styles can run normally in wp-admin.
• Consider whether the ?with-admin-transitions repro override is still useful or should be removed with the workaround.

Start by checking Chromium issue 530704642 and the workaround in packages/playground/remote/src/lib/playground-worker-endpoint.ts. After the fix reaches stable Chrome or Edge, verify the crash no longer reproduces, then inspect the admin transition behavior and decide whether the ?with-admin-transitions override is still needed. Done means the Chromium-only workaround is removed and fallback transitions and wp-view-transitions-admin styles work normally in wp-admin.