You do not have to deliberately fail. All you have to do is not to meet the unprecedented demands. Keep yourself in a state where it is impossible to perform DC 42 checks in Knowledge (Nature), Knowledge (Geography) and Survival is not difficult, especially in view of the strict limitations on technical assistance
Attention, it is not completely free. You will have to find 500 gp of Adamantium by casting. This will cost you 1000gp in diamond dust for the Restoration. This will cost you 100 GP for the magic pot, and, for the non-devilish path, 1000 GP for the clone. You must also fail your backup, but it is voluntary.
Dispelling the magic does not work because Flesh to Stone is instant, rather than duration. Flesh to stone is also at the 6th level, which means that Break Enchantment will only work if it can be broken by Dissipation of Magic or Stone to Flesh. Mythical break Enchantment would do the trick, but if someone casts you mythical spells, you probably already have problems.
Stone to Flesh is … questionable. He is aiming for either a petrified creature or a quantity of stone. If you are categorical, you are not a quantity of stone, and broken / sliced pieces are clearly not a creature. Moreover, Flesh to Stone makes no reference at all to the petrified state, and the petrified state itself specifically says that it refers to a state that has been turned into stone (this which, again, is not categorical). A DM may well assert that Stone to Flesh's goal is to counter Flesh to Stone, and therefore that it works, but he should have also decided that removed parts of the statue (such as limbs) would still count as parts of the creature, in a way that is simply not for removed parts of a non-petrified standard creature.
On the bright side, even if the SM is right against you on Stoen to Flesh, all is not lost. Very few people would think that throwing Stone to Flesh on an unyielding golem would make sense, to the point that if someone tries it and there are no hostile deities involved, it's almost certainly because the DM abuses knowledge of the OOC. Break Enchantment is a more plausible tactic, but the casting time is one minute during which the Golem has the opportunity to formulate objections to the process.
In addition, if you are evil, there is a way to do it that requires much less spell casting. Find a miserable one not to be missed and apply the appropriate levels of mind control or diplomacy to convince him that you are a friend. Teach him the ritual. To have him launch it, solo. Be sure to hit him with something that makes him lose his backup bonus, and maybe something that will feed him from time to time to the point that the 6d6 damage will not kill him outright. (If he's dead, he's no longer a valid target for Flesh to Stone.)
Of course, this is the kind of resource-generating system that leaves traces and can produce interesting complications. You have to find the ritual, you have to learn it, and since the ritual literally attempts (whatever it is) to steal all that is categorical in an area whose radius is measured tens of kilometers, it seems be it that kind of thing. this could attract attention.
Last warning: for the ritual, the mineral / metal / gemstone must be "natural". As a skymetal, adamant may or may not be eligible, depending on the exact definition of "natural". His Probably agree, but your deputy minister may disagree.