Update trigger.spec.filters to the latest subscription API filters

[pierDipi]

Problem

The subscription API has been updated to improve the UX in
cloudevents/spec#957

We should update the new-trigger-filter experimental feature to reflect that.

Persona:
Which persona is this feature for?
Event consumer

Exit Criteria

A measurable (binary) test that would indicate that the problem has been resolved.

Time Estimate (optional):
How many developer-days do you think this may take to resolve?
2

Additional context (optional)

/area brokers

[github-actions]

This issue is stale because it has been open for 90 days with no
activity. It will automatically close after 30 more days of
inactivity. Reopen the issue with /reopen. Mark the issue as
fresh by adding the comment /remove-lifecycle stale.

[pierDipi]

/remove-lifecycle stale

[daisy-ycguo]

I would like to work on this issue.
/assign

[pierDipi]

There is one missing update for https://github.com/knative/eventing/tree/main/pkg/eventfilter/subscriptionsapi to accept multiple entries for the updated filters (for example

eventing/pkg/eventfilter/subscriptionsapi/exact_filter.go

Line 39 in c884e27

func NewExactFilter(attribute, value string) (eventfilter.Filter, error) {

accepts only one entry), so reopening for now.