[SECURITY] Prevent credential leakage in GitHook by removing auth from repo URL

[abhijeets25012-tech]

Problem

Currently, GitHook embeds credentials (username/token) directly in the repository URL for HTTP(S) connections.
This can cause sensitive information to be exposed in DAG parsing, logs, or .git/config.

Solution

• Removed embedding credentials in the URL.
• Added secure token-based authentication using GIT_ASKPASS.
• Disabled interactive prompts with GIT_TERMINAL_PROMPT=0.
• Preserved SSH support for git@ URLs and local paths.
• Fully backward-compatible; does not affect existing SSH workflows.

Security Impact

• Prevents cleartext credentials from being persisted in Git configuration.
• Ensures DAG authors cannot accidentally exfiltrate tokens during parsing.

Testing

• Verified repo URLs with/without tokens.
• Confirmed SSH keys and GIT_ASKPASS work as expected.

[potiuk]

@abhijeets25012-tech This PR has been converted to draft because it does not yet meet our Pull Request quality criteria.

Issues found:

• ❌ Merge conflicts: This PR has merge conflicts with the main branch. Your branch is 258 commits behind main. Please rebase your branch (git fetch origin && git rebase origin/main), resolve the conflicts, and push again. See contributing quick start.

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