Fix code scanning alert no. 111: Incomplete URL substring sanitization

[laipz8200]

Fixes https://github.com/langgenius/dify/security/code-scanning/111

To fix the problem, we need to parse the URL and ensure that the host is correctly validated. Instead of using startswith and endswith, we will use the urlparse function from the urllib.parse module to extract the hostname and validate it.

1. Parse the URL using urlparse.
2. Check if the hostname is "github.com".
3. Ensure the path ends with ".yml" or ".yaml".
4. Replace the URL parts to convert it to the raw GitHub URL if the checks pass.

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