Improve .gitmodules file handling in scan_content_warn

[0xScratch]

While exploring coldclone, I ran into a weird TypeError related to .gitmodules when scanning a Sherlock audit repository (TARE). Here's the .gitmodules present in the repo:

[submodule "tare-io__tare-contracts/lib/solmate"]
	path = tare-io__tare-contracts/lib/solmate
	url = https://github.com/transmissions11/solmate
[submodule "tare-io__tare-contracts/lib/forge-std"]
	path = tare-io__tare-contracts/lib/forge-std
	url = https://github.com/foundry-rs/forge-std
[submodule "tare-io__tare-contracts/lib/createx-forge"]
	path = tare-io__tare-contracts/lib/createx-forge
	url = https://github.com/radeksvarz/createx-forge
[submodule "tare-io__tare-contracts/lib/safe-smart-account"]
	path = tare-io__tare-contracts/lib/safe-smart-account
	url = https://github.com/safe-global/safe-smart-account
[submodule "tare-io__tare-contracts/lib/openzeppelin-contracts"]
	path = tare-io__tare-contracts/lib/openzeppelin-contracts
	url = https://github.com/OpenZeppelin/openzeppelin-contracts

And when coldclone was run on this repo, I got the following error:

WARN could not parse .gitmodules (TypeError); review manually

After digging in the issue, and checking the two main functions i.e. _warn_gitmodules and scan_content_warn, it turns out that the issue is related to some newline thing which even has a comment explaining why it's there:

def scan_content_warn(repo: Path) -> list[str]:

...

    elif nm == ".gitmodules":
        # newline="" preserves \r so the CVE-2025-48384 CR vector is
        # not silently translated to \n before _warn_gitmodules sees it
        out += _warn_gitmodules(
            rel, p.read_text(encoding="utf-8", errors="replace", newline=""))

...

    return out

The issue is that, Path.read_text() only accepts the newline parameter starting from Python 3.13, causing .gitmodules scanning to fail with a TypeError on Python 3.11 and 3.12, despite the project indicating support for Python >= 3.11.

So I think a better approach is to use Path.open(..., newline=""), which preserves the intended behaviour while remaining compatible with earlier supported python versions. The fixed code snippet looks like:

def scan_content_warn(repo: Path) -> list[str]:

...

    elif nm == ".gitmodules":
        # newline="" preserves \r so the CVE-2025-48384 CR vector is
        # not silently translated to \n before _warn_gitmodules sees it
        with p.open(
            "r", encoding="utf-8", errors="replace", newline=""
        ) as f:
             out += _warn_gitmodules(rel, f.read())

...

    return out

This removes the TypeError while preserving the intended newline behaviour. Additionally, just for precaution sake, I also checked whether this new fix doesn't break anything related to .gitmodules by adding various weird urls. Thankfully, it doesn't and still gives warning for weird stuff!