Refactor chunk processing and update version commit

Optimize chunk processing by moving variable declarations inside the loop and update the commit hash in version.go to reflect the latest changes.

pkg/obioptions/version.go

@@ -8,7 +8,7 @@ import (
 // corresponds to the last commit, and not the one when the file will be
 // commited
 
-var _Commit = "547135c"
+var _Commit = "f55dd55"
 var _Version = "Release 4.4.0"
 
 // Version returns the version of the obitools package.