fix(release): install uv inside PSR container before uv build

[ckrough]

The v0.2.0 release attempt on b4d5270 aborted with Build command failed with exit code 127 because the python-semantic-release@v10.5.3 action runs in a Docker container that ships Python 3.14 but not uv. My PR #39 set build_command = "uv build" assuming the project's host toolchain was available; it isn't.

Fix

-build_command = "uv build"
+build_command = "python -m pip install uv && uv build"

One-time pip install uv cost per release (~3 s). Keeps the project's uv-first toolchain at build time; alternative was python -m pip install build && python -m build which would diverge from the rest of the build flow.

Failure evidence

Failed run: https://github.com/ckrough/drover/actions/runs/25671079007

[12:49:20] INFO     Found 2 commits since the last release!
[12:49:20] INFO     The type of the next release release is: minor
0.2.0
...
[12:49:21] ERROR    Command '['bash', '-c', 'uv build']' returned non-zero exit status 127.
[12:49:21] ERROR    Build command failed with exit code 127
Build failed, aborting release

PSR computed the next version correctly (0.2.0 minor bump from PR #38's feat(taxonomy)). The failure was entirely at the build_command invocation; no commit, tag, or release artifact landed.

After merge

The push will re-trigger release.yml on this merge commit. PSR will once again see the feat: from PR #38 plus the fix: from this PR since v0.1.0, compute a minor bump to v0.2.0, install uv, build sdist + wheel, commit chore(release): 0.2.0, tag v0.2.0, and create the GH Release with both artifacts attached.