SECURITY UPDATE: Configuration file injection via unescaped carriage
returns in ConfigParser.write()
debian/patches/CVE-2026-0864.patch: normalize CR, CRLF and LF line
endings to '\n\t' in both value-escaping call sites of
RawConfigParser.write() in Lib/ConfigParser.py, so an attacker
controlled value can no longer inject unexpected keys into the written
file; add regression test to Lib/test/test_cfgparser.py