VersionFull pins 1.4.3; upstream netcode is now 1.4.4 #22

netcode.go pins VersionFull at 1.4.3 and CI carries a check named VersionFull matches upstream. Upstream netcode cut v1.4.4 today (strict floating-point builds, no wire change), so that check will demand the follow-up on its next run against the new upstream release. The bump is small: update VersionFull to 1.4.4, let the wire-compat gate prove nothing moved, and cut the next tag.