aws: fix NextToken invalidation in paginated queries

Remove the upper time bound from Security Hub, GuardDuty, and
Inspector httpjson templates. The httpjson input re-evaluates
request.transforms on every pagination page, so (now) in the
filter body changes between pages. When the value crosses a time
boundary, AWS rejects the NextToken with "Input Query has changed".

The lower bound from the cursor remains stable during pagination
and provides sufficient windowing. A CEL rewrite can reintroduce
the upper bound safely since it can pin the value once per
collection interval.

Without an upper bound, findings created during pagination could
extend the result set. Since results are sorted ascending by update
time, new findings appear at the tail. The creation rate would need
to exceed the pagination rate (~60 findings/second at 100 per page)
to cause unbounded pagination. Security Hub, GuardDuty, and
Inspector finding rates are orders of magnitude below this.