typechain-hardhat does not consider hardhat 'sources' config

Hardhat allows you to move your contracts folder: https://hardhat.org/hardhat-runner/docs/config#path-configuration

When config.paths.sources is nonstandard, typechain-hardhat refuses to generate types.

for example:

```ts
const config: HardhatUserConfig = {
solidity: "0.8.18",
paths: {
artifacts: "./hardhatstuff/artifacts",
cache: "./hardhatstuff/artifacts/cache",
sources: "./hardhatstuff/contracts",
},
typechain: {
discriminateTypes: true,
outDir: "./hardhatstuff/artifacts/typechain-types",
},
};
```

```
➜ /workspace git:(master) ✗ npx hardhat clean && npx hardhat compile
Generating typings for: 3 artifacts in dir: ./hardhatstuff/artifacts/typechain-types for target: ethers-v6
Successfully generated 0 typings!
Compiled 3 Solidity files successfully (evm target: paris).
```

```
Versions:
"@nomicfoundation/hardhat-ethers": "^3.0.4",
"@nomicfoundation/hardhat-toolbox": "^3.0.0",
"@openzeppelin/contracts": "^4.9.3",
"@typechain/ethers-v6": "^0.4.3",
"@typechain/hardhat": "^8.0.3",
"ethers": "^6.7.1",
"hardhat": "^2.18.0",
"typechain": "^8.3.1"
```

Incidentally, it appears if I move it to the default location, compile, then move it back, subsequent compiles properly do types...