chore: update cbtc example

[lgalabru]

This PR is highlighting how to use pyth locally.
When running the clarinet REPL with the following command, loading the default simnet deployment plan:

$ cd example/cbtc
$ clarinet console -d

and evaluating the following expression:

>> (contract-call? 'ST2T5JKWWP3FYYX4YRK8GK5BG2YCNGEAEY1JKX06E.pyth-governance-v1 get-current-execution-plan)

developers should observe the following versions:

{ 
    pyth-decoder-contract: 'ST2T5JKWWP3FYYX4YRK8GK5BG2YCNGEAEY1JKX06E.pyth-pnau-decoder-v1, 
    pyth-oracle-contract: 'ST2T5JKWWP3FYYX4YRK8GK5BG2YCNGEAEY1JKX06E.pyth-oracle-v2, 
    pyth-storage-contract: 'ST2T5JKWWP3FYYX4YRK8GK5BG2YCNGEAEY1JKX06E.pyth-store-v1, 
    wormhole-core-contract: 'ST2T5JKWWP3FYYX4YRK8GK5BG2YCNGEAEY1JKX06E.wormhole-core-v2
}

[Patotking12]

Hey @lgalabru I see you changed everything to testnet, I've been trying to use it on mainnet , but haven't been able to do so... i always get an error

[lgalabru]

@ali-bahjati I'll go ahead and merge this branch, none of these changes are impacting the contracts, we've simply updated the cbtc-example, now outlining how developers can locally build on top of Pyth, and how these integrations can be unit tested.