Add a github action to create a tenderly testnet to cast the spell

[0x3phemeralsoul]

• We need an API key that is used to generate an RPC for each run.
• API Key is owned by TechOPS
• Document ownership of the API(which team/project on Tenderly owns the RPC in case it stops working we can address it without downtime for spell crafting/reviewing

Acceptance

• Current CD/CI action remains using TechOps RPC.
• Decide whether the actions is automatically triggered or manually.
• TechOps to provide API key for RPC on tenderly

[SidestreamColdMelon]

#388 is merged, so this one is unblocked

[SidestreamColdMelon]

Note: there is workflow_dispatch event that you might use at first to automate cast-on-tenderly-script before trying to completely automate casting inside a PR (which would require at least adding "testnet deletion" functionality which can blow up the scope)