Missing schema definitions causing configuration validation warnings in Bootstrap Barrio 5.5.20

Problem/Motivation

## Issue Summary
Bootstrap Barrio version 5.5.20 generates multiple configuration schema validation warnings due to missing schema definitions for region width settings and utility configurations. This affects Drupal 11.2.x installations.

## Problem Description

### Error Message
When running `drush config:inspect --only-error`, the following schema validation warnings appear:

```
Schema errors for bootstrap_barrio.settings with the following errors:
bootstrap_barrio.settings:bootstrap_barrio_region_width_top_header missing schema, ... and so on.

Steps to reproduce

1. Install Drupal 11.2.2
2. Install Bootstrap Barrio theme version 5.5.20
3. Enable Bootstrap Barrio theme
4. Run `drush config:inspect --only-error`
5. Observe the 25 schema validation errors for `bootstrap_barrio.settings`

### Environment
- **Drupal Core**: 11.2.2
- **PHP Version**: 8.3.6
- **Bootstrap Barrio Version**: 5.5.20
- **Installation Method**: Composer

Proposed resolution

## Root Cause Analysis
The issue occurs because the theme's configuration includes settings for region widths and utility options that are present in the default configuration but are not defined in the schema file `config/schema/bootstrap_barrio.schema.yml`.

The missing configurations are being set in the theme but lack corresponding schema definitions, causing Drupal's configuration validation to flag them as errors.

## Proposed Fix

### Files Affected
- `config/schema/bootstrap_barrio.schema.yml`

### Schema Additions Required
Add the following schema definitions to the `bootstrap_barrio.settings` mapping section:

```yaml
# Region widths.
# ----------------------------
bootstrap_barrio_region_width_top_header:
type: integer
label: 'Width for Top header region'
bootstrap_barrio_region_width_top_header_form:
type: integer
label: 'Width for Top header form region'
bootstrap_barrio_region_width_header:
type: integer
label: 'Width for Header region'
bootstrap_barrio_region_width_header_form:
type: integer
label: 'Width for Header form region'
bootstrap_barrio_region_width_primary_menu:
type: integer
label: 'Width for Primary menu region'
bootstrap_barrio_region_width_secondary_menu:
type: integer
label: 'Width for Secondary menu region'
bootstrap_barrio_region_width_page_top:
type: integer
label: 'Width for Page top region'
bootstrap_barrio_region_width_page_bottom:
type: integer
label: 'Width for Page bottom region'
bootstrap_barrio_region_width_highlighted:
type: integer
label: 'Width for Highlighted region'
bootstrap_barrio_region_width_featured_top:
type: integer
label: 'Width for Featured top region'
bootstrap_barrio_region_width_breadcrumb:
type: integer
label: 'Width for Breadcrumb region'
bootstrap_barrio_region_width_content:
type: integer
label: 'Width for Content region'
bootstrap_barrio_region_width_sidebar_first:
type: integer
label: 'Width for Sidebar first region'
bootstrap_barrio_region_width_sidebar_second:
type: integer
label: 'Width for Sidebar second region'
bootstrap_barrio_region_width_featured_bottom_first:
type: integer
label: 'Width for Featured bottom first region'
bootstrap_barrio_region_width_featured_bottom_second:
type: integer
label: 'Width for Featured bottom second region'
bootstrap_barrio_region_width_featured_bottom_third:
type: integer
label: 'Width for Featured bottom third region'
bootstrap_barrio_region_width_footer_first:
type: integer
label: 'Width for Footer first region'
bootstrap_barrio_region_width_footer_second:
type: integer
label: 'Width for Footer second region'
bootstrap_barrio_region_width_footer_third:
type: integer
label: 'Width for Footer third region'
bootstrap_barrio_region_width_footer_fourth:
type: integer
label: 'Width for Footer fourth region'
bootstrap_barrio_region_width_footer_fifth:
type: integer
label: 'Width for Footer fifth region'
bootstrap_barrio_region_clean_none:
type: integer
label: 'Clean wrapper for None region'
bootstrap_barrio_region_width_none:
type: integer
label: 'Width for None region'
bootstrap_barrio_region_class_none:
type: string
label: 'Classes for None region'
```

### Placement
These definitions should be added after the existing footer region definitions (around line 160) and before the "Sidebar position" section in the schema file.

## Testing
After applying the fix:
1. Clear Drupal cache: `drush cache:rebuild`
2. Run configuration inspection: `drush config:inspect bootstrap_barrio.settings`
3. Verify no schema errors are reported
4. Confirm theme functionality remains intact

## Expected Result
- ✅ Zero schema validation errors for `bootstrap_barrio.settings`
- ✅ All theme functionality preserved
- ✅ Configuration validation passes cleanly

## Impact
- **Severity**: Minor (cosmetic warnings, no functional impact)
- **Affected Versions**: Bootstrap Barrio 5.5.20 (possibly earlier versions)
- **Drupal Versions**: Drupal 11.x

Remaining tasks

User interface changes

API changes

Data model changes