devel/cssc: Improve, lint, take maintainership
- Clarify the LICENSE
- Add LICENSE_FILE
- Remove BROKEN_mips* stances as MIPS is going to be unsupported and irrelevant with STABLE-13 EOL (since May 2026)
PR: 294560
Approved by: db@, yuri@ (Mentors, implicit)
MFH: 2026Q2
(cherry picked from commit a82172729b95845687e3551fbe06e4a347bccba8)