sign_pkg fails to overwrite signature when rebuilding package

[iyanmv]

Affected Version

paru v2.1.0 - libalpm v15.0.0

Description

Since I don't have permission to reopen my old bug report I create this new one here.

There is no need to share logs. This is how you can reproduce the issue.

1. Configure paru with chroot and a local repo
2. Build a package
3. Rebuild the same package

Expected result

The local repo contains the last rebuild with a valid signature.

Actual result

The local repo contains the second rebuild but keep the signature of the first build. This makes the installation to fail since the signature is not valid.

Proposed fix

I opened a PR (#1389) with a fix that solves my issue. But since I'm not very familiar with the rest of the code, please double check if this might have some undesired effects. I have been using this patch for months since paru 2.0.4 without issues. And recently I updated to 2.1.0 with the same patch.