Log Message:
www/squid6: update to 6.5

Changes in squid-6.5 (6 Nov 2023):

- Remove mem_hdr::freeDataUpto() assertion
- Bug 5309: frequent "lowestOffset () <= target_offset" assertion
- Exit without asserting when helper process startup fails
- RFC 1123: Fix date parsing
- Improve handling of expanding HTTP header values
- Maintenance: reduce output of CONTRIBUTORS update script