Update using-pyth-price-feeds.md (#314)

This commit updates the tutorial documentation on using Pyth Price Feeds with Foundry to fix a TOML parse error encountered by users when setting up the foundry.toml file. The issue was identified in the "Installing Pyth smart contracts" section, where mismatched quotation marks in the remappings line caused a parse error. The original line used inconsistent quotes.

The fix involves correcting the quotation marks to ensure consistency, thereby preventing the TOML parse error:
`remappings = ['@pythnetwork/pyth-sdk-solidity/=lib/pyth-sdk-solidity']`

apps/base-docs/docs/building-with-base/guides/using-pyth-price-feeds.md

@@ -114,7 +114,7 @@ forge install pyth-network/[email protected] --no-git --no-commit
 Once installed, update your `foundry.toml` file by appending the following line:
 
 ```bash
-remappings = ['@pythnetwork/pyth-sdk-solidity/=lib/pyth-sdk-solidity’]
+remappings = ['@pythnetwork/pyth-sdk-solidity/=lib/pyth-sdk-solidity']
 ```
 
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