[subvolume_charge.sh]: Fix Argument Parsing

[andthum]

[subvolume_charge.sh]: Fix Argument Parsing

Type of Change

• Bug fix.
• New feature.
• Code refactoring.
• Dependency update.
• Documentation update.
• Maintenance.
• Other: Description.

• Non-breaking (backward-compatible) change.
• Breaking (non-backward-compatible) change.

Motivation and Context

binwidth was read from the 9th positional argument (like every) although it must be read from the 10th positional argument.

Proposed Changes

Read binwidth from the 10th positional argument.

PR Checklist

• I followed the guidelines in the Developer's Guide.
• New/changed code is properly tested.
• [~] New/changed code is properly documented.
• New/changed features are tracked in CHANGELOG.rst.
• The CI workflow is passing.