tests/clickhouse-test-runner: stop logging argv (#739)

## Summary

The harness was logging the entire raw `argv` of every invocation. The
previous attempt filtered it through a hand-rolled parser; since we
don't go through a real argv-parsing library, drop the log line entirely
rather than ship a second parser to maintain.

- **`src/main.ts`**: remove the `argv=` log line.
- **`src/args.ts`**: remove the `extractKnownArgv` helper introduced in
the prior commit.
- **`__tests__/args.test.ts`**: remove the corresponding tests.

## Checklist

- [x] A human-readable description of the changes was provided to
include in CHANGELOG

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: Peter Leonov <peter.leonov@clickhouse.com>

Author: Copilot

package-lock.json

@@ -17,7 +17,6 @@ async function main(): Promise<void> {
   const logPath = resolveLogPath()
   appendLog(logPath, '=== clickhouse-client invocation ===')
   appendLog(logPath, 'timestamp=' + new Date().toISOString())
-  appendLog(logPath, 'argv=' + JSON.stringify(argv))
 
   let args
   try {