Refresh generated Citus image requirements

[ihalatci]

Summary

• regenerate the tester image requirement files from the updated Citus Pipfile.lock
• refresh the failtester, citusupgradetester, and pgupgradetester runtime requirements using pipenv requirements
• refresh the stylechecker requirements using pipenv requirements --dev-only
• drop the old forked mitmproxy reference in favor of the current upstream-generated output

Notes

These files are maintained as generated artifacts, so this PR follows the generation instructions in the headers rather than copying ad hoc exports directly.

Verification

• confirmed the requirement files no longer reference the forked citusdata/mitmproxy source
• verified the refreshed pins include mitmproxy 12.2.2, cryptography 46.0.7, pytest 9.0.3, Werkzeug 3.1.6, tornado 6.5.5, and black 26.3.1
• installed the refreshed requirement sets in clean Python 3.12 environments and ran pip check successfully