Reapply "build: Don't check parent directories for git tag"
This reverts commit 7e0c25eccd8d9bc5b77953dbc9a39a26e383c550.
The `--git-dir` argument is relative to the `-C` argument, making this
patch OK after all.
I added a comment to go along with this since I found it confusing.
Apologies for the revert.
1eb729b9b9Andrew Kelley committed on 3/8/2025, 8:34:13 PMparent0bce4a4