Don't worry about it
The Pathfinder Unchained summoner, like the original summoner, has the following text describing the class feature eidolon:
The eidolon forms a link with the summoner, who forever after summons an aspect of the same creature.
Unless an effect's severed the link the eidolon forms with the summoner, the summoner brings forth only an aspect of the creature to whom the summoner's linked, not the actual creature to whom he's linked, just like a normal summoning spell (albeit with vastly increased complexity), not a calling spell. This makes permanent removal of the eidolon class feature a plot issue not a rules issue. (That is, the creature to whom the summoner is linked is never given a precise location or statistics, so what's preventing the eidolon from sending eidolon aspects when the summoner asks is GM fiat or specific effects that prevent summoning.)1
In other words, the linked eidolon can't die unless the DM just says such a thing happens. And unless that happens, the eidolon aspect probably can't permanently die either, but there's some debate in Pathfinder Society if an ability damaged or diseased eidolon that's resummoned remains ability damaged or diseased.2
I searched Paizo's Pathfinder Society messageboards for further information about this topic and found nothing addressing it directly (and it appears even eidolon deaths in combat are uncommon, so eidolon deaths by GM fiat even moreso?). However, if planning for long-term play, this thread and this thread wondering about tracking eidolon's injuries from scenario to scenario might be of interest.
1 A longer and even more extreme version of eidolon aspect destruction ("Your eidolon is stuck 100 years in the future," said DM Nelson. "Ha ha!") that I believe can still be remedied is detailed here.
2 I would argue a lot that The eidolon doesn't heal naturally applies only to hp, as that's the statement's context. Applying that to everything seems deeply against the statement spirit, and literally means, for example, any psychological trauma the eidolon suffers never heals, and that's just sad.
Check on the Paizo Store.
One of the sections in the Paizo online store is the Replayable Scenarios section. This has all of the currently-purchasable Tier 1-2 scenarios that Paizo sells. It's not a complete list on it's own, but it is certainly authoritative. To find the others...
Ask on the Paizo forums.
I hate giving an answer like this, but after an hour of searching online I'm pretty confident in saying that there are no easily-accessible lists of Pathfinder Society adventures outside of the Paizo store. According to this thread from March 2016, there are several adventures that count as evergreen that I can't find on the Paizo store. Since the list of applicable scenarios is going to change season-to-season, in this case the quickest way to get a pretty good list of evergreen adventures would be to ask on the general Pathfinder Society forums.
Check yourself.
As a final option, it's also possible for you to check if a particular adventure is evergreen yourself. The rule for what counts as evergreen is pretty simple:
All Tier 1 and 1-2 adventures can be replayed an unlimited
number of times with a 1st-level character for credit.
So, if you have an adventure that's either Tier 1 or Tier 1-2 and is playable in the current season, then that adventure is evergreen.
Best Answer
There does not seem to be a way (currently)
As a Limited option, you must have a Boon that specifically says you gain access to it. Going through the List of Boons available (link to your account on Paizo.com), there is no mention of inner radiance torrent, "Limited" (looking for something along the lines of "Select a limited spell from a curated list..."), nor any general access to Secrets of Magic elements*.
*This isn't quite true because Esoteric Spellcaster - Secrets of Magic exists. However, it only provides access to Uncommon spells, specifically nudge the odds, spiritual attunement or zero gravity.