Handle locked pip version on Windows

[radoering]

Resolves: #6138

Use poetry -m pip ... instead of calling pip directly so that pip can update itself on Windows.

Just to be sure that this has no influence on performance, a little test:

setup = "import subprocess"

variants = {
    'embedded': [PYTHON_PATH, EMBEDDED_PIP_PATH, "-V"],  # fallback + prior #6062
    'bin': [PYTHON_PATH, PIP_PATH, "-V"],  # current
    'module': [PYTHON_PATH, "-m", "pip", "-V"],  # new
}

for name, cmd in variants.items():
    stmt = f"subprocess.check_output({cmd})"
    print(f"{name}: {timeit(stmt, setup, number=5)}")

Sample output:

embedded: 5.4903443
bin: 1.8143028999999995
module: 1.7508081999999998

As expected it makes no difference whether pip is called directly or as module.

[neersighted]

LGTM -- glad this was as simple as I asserted it was 😆

[poetry-bot]

The backport to 1.2 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-1.2 1.2
# Navigate to the new working tree
cd .worktrees/backport-1.2
# Create a new branch
git switch --create backport-6430-to-1.2
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 b9ed1f052fec72ec5dc83c3923d56159ac7fb325
# Push it to GitHub
git push --set-upstream origin backport-6430-to-1.2
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-1.2

Then, create a pull request where the base branch is 1.2 and the compare/head branch is backport-6430-to-1.2.

[github-actions]

This pull request has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.