Packaging: Use pip list --format=json for better parsing

[edvilme]

According to the docs, pip list supports a JSON format for output, which is better suited for computer parsing without having to worry about rendering edge cases or building custom parsing logic.

[Copilot]

Pull request overview

This PR updates the built-in package refresh flow to use pip list --format=json and switches parsing from custom text parsing to JSON parsing, aiming for more reliable machine-readable output.

Changes:

• Update package listing commands to request JSON output (--format=json) and parse it via a new JSON parser.
• Replace the previous text-based pip list parser with parsePipListJson() (JSON-based).
• Update and expand unit tests to cover JSON parsing plus a couple of edge cases.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/managers/builtin/utils.ts	Switches package refresh to pip list --format=json and uses the JSON parser (also adds uv args for JSON).
src/managers/builtin/pipListUtils.ts	Replaces text parsing with JSON parsing (parsePipListJson).
src/test/managers/builtin/pipListUtils.unit.test.ts	Updates unit tests to validate JSON parsing and adds edge-case tests.
src/test/managers/builtin/piplist1.actual.txt	Removes legacy text output fixture.
src/test/managers/builtin/piplist2.actual.txt	Removes legacy text output fixture.
src/test/managers/builtin/piplist3.actual.txt	Removes legacy text output fixture.

Comments suppressed due to low confidence (1)

src/managers/builtin/utils.ts:208

• runPython() currently concatenates stdout + stderr into the returned string (see helpers.ts), but pip list --format=json needs the returned data to be valid JSON. Any pip notices/warnings written to stderr (common on success) will corrupt the JSON and make parsePipListJson() return [], silently hiding packages. Consider changing this call to use a helper that returns stdout only (while still logging stderr), or adjust runPython() to optionally not append stderr for JSON-producing commands.

    try {
        return await runPython(
            environment.execInfo.run.executable,
            ['-m', 'pip', 'list', '--format=json'],
            undefined,
            log,
            undefined,
            PIP_LIST_TIMEOUT_MS,
        );