[python] version.py: guard git calls during wheel builds (sans .git)

[ryan-williams]

Issue and/or context: #2588

Changes:
Make sure "version inference from Git tags" fails silently/gracefully when run outside of a Git clone (e.g. during wheel build).

Notes for Reviewer:

Here is a passing "sdist & wheel build" GHA dispatched from this branch.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.26%. Comparing base (12566dd) to head (6ffee30).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2590   +/-   ##
=======================================
  Coverage   90.26%   90.26%           
=======================================
  Files          37       37           
  Lines        4007     4007           
=======================================
  Hits         3617     3617           
  Misses        390      390           

Flag	Coverage Δ
python	90.26% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Components	Coverage Δ
python_api	90.26% <ø> (ø)
libtiledbsoma	∅ <ø> (∅)

[ryan-williams]

"sdist & wheels" GHA succeeded on this branch.

Here's a local test I also ran:

test_wheel_build

test_wheel_build() {
    if [ $# -gt 1 ]; then
        echo "Usage: test_wheel_build [branch=main]" >&2
        return 1
    elif [ $# -eq 1 ]; then
        branch="$1"; shift
    else
        branch=main
    fi

    now=`date +%s`
    dir=/tmp/tiledb-soma-$now
    echo "Cloning TileDB-SOMA@$branch to $dir" >&2
    git clone --depth 1 -b $branch https://github.com/single-cell-data/TileDB-SOMA $dir
    cd $dir/apis/python

    echo "Building wheel" >&2
    python setup.py sdist
    tar=`ls dist`
    name="${tar%.tar.gz}"
    mv dist/$tar /tmp/  # move back up to /tmp, outside the Git clone
    cd /tmp

    echo "Extracting $tar into /tmp/$name" >&2
    tar -xvf $tar
    cd $name

    echo 'Testing `python version.py`' >&2
    python version.py
}

test_wheel_build         # ❌ currently fails against `main`
# subprocess.CalledProcessError: Command '('git', 'tag', '--list', '--sort=v:refname', '[0-9].*.*')' returned non-zero exit status 128.
test_wheel_build rw/ver  # ✅ succeeds against this branch
# 1.11.1.post0.dev117435952

[jdblischak]

I manually triggered the packaging CI workflow for this branch, and it passed

https://github.com/single-cell-data/TileDB-SOMA/actions/runs/9161462896

[github-actions]

The backport to release-1.11 failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-release-1.11 release-1.11
# Navigate to the new working tree
cd .worktrees/backport-release-1.11
# Create a new branch
git switch --create backport-2590-to-release-1.11
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick --mainline 1 60344e20d2d19333a1d54fca74af297ca0a214ac
# Push it to GitHub
git push --set-upstream origin backport-2590-to-release-1.11
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-release-1.11

Then, create a pull request where the base branch is release-1.11 and the compare/head branch is backport-2590-to-release-1.11.