Update version to 10.3.4

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Add release notes for the 10.3.4 release

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
docs: Add sha256 sums for the 10.3.4 release

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>