Open3.pm:spawn_with_handles remove alot of duplicate operators

dont call fileno twice, don't deref key "open_as" 3 extra times.
Move two variable assignments outside of parens.

Done for readability. Remove some unused variables. Move declaration of other
variable closer to where it is used. Rationalize indentation on lines
modified. Increment $VERSION.

For: RT #122282 (additional)