Retire the summary hover E2E spec pinned to removed surfaces

The quarantined 48-summary-hover-selection spec never ran, and none of
its nine tests could pass against the current app. Each one opens
/workloads or /storage, which no route matches since the platform-first
IA, or /infrastructure, which is now only an entry route that redirects
to the first platform page, and then waits for the workloads,
infrastructure or storage summary cards that were deleted with the
standalone surfaces.

The storage pool-group pin test was the only candidate for a port to
/proxmox/storage, but it asserts behaviour that page does not have. A
group-header click there collapses the group as it pins it, so the
member rows the test expects to stay visible and pinned are hidden, and
there are no summary charts left for the pin to rescope. The live pin
(hover preview, the summaryGroup URL param, pinned member emphasis
after expanding, Clear selection) is already covered in Storage.test.tsx.

Deleting the file takes its QUARANTINED_SPECS entry with it, because
the tier check rejects ledger entries for specs that do not exist.

tests/integration/e2e-tiering.mjs

@@ -10,7 +10,6 @@ export const QUARANTINED_SPECS = [
   // spec turns that open bug into a permanent red.
   '**/03-multi-tenant.spec.ts',
   '**/47-inline-selection-scroll-stability.spec.ts',
-  '**/48-summary-hover-selection.spec.ts',
 ];
 
 /**