Revert "build: Don't check parent directories for git tag"

This reverts commit 21620f3c652bc874776acc7251f05b25d2838019.

This breaks running `zig build` from subdirectories.
7e0c25eccdAndrew Kelley committed on 3/8/2025, 7:15:44 PMparent21620f3
1 file changedLine totals unavailable