docs: remove draft warning from combobox

[laske185]

This pull request makes a small documentation update to the Combobox component's readme file. The change removes a warning message about the component being untested and not recommended for production use.

Closes #7815

The A11y and PO reviews will only take place after all other DoD steps have been completed by the Developer:

• Meaningful pull request title for the release notes
• Pull request is linked to an issue and all changes relate to the issue
• Tests to protect this code implemented (if applicable)
• Manual test performed successfully (if applicable)
• Documentation or migration has been updated (if applicable)

[github-actions]

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[github-actions]

Hydration Benchmark Report (vs Baseline)

📊 Flop 5 Regressions

Component	Current	Baseline	Δ%	Result
kol-indented-text	8ms	6ms	+33.3%	🔻
kol-logo	5ms	4ms	+25.0%	🔻
kol-tree	10ms	8ms	+25.0%	🔻
kol-image	6ms	5ms	+20.0%	🔻
kol-spin	6ms	5ms	+20.0%	🔻

📋 Show all results

Component	Current	Baseline	Δ%	Result
kol-abbr	19ms	18ms	+5.6%	🔻
kol-accordion	66ms	63ms	+4.8%	➖
kol-alert	24ms	21ms	+14.3%	🔻
kol-avatar	11ms	10ms	+10.0%	🔻
kol-badge	32ms	32ms	0.0%	➖
kol-breadcrumb	16ms	15ms	+6.7%	🔻
kol-button	47ms	45ms	+4.4%	➖
kol-button-group	7ms	6ms	+16.7%	🔻
kol-button-link	48ms	44ms	+9.1%	🔻
kol-card	13ms	11ms	+18.2%	🔻
kol-details	61ms	57ms	+7.0%	🔻
kol-drawer	8ms	8ms	0.0%	➖
kol-form	9ms	9ms	0.0%	➖
kol-heading	11ms	10ms	+10.0%	🔻
kol-icon	9ms	8ms	+12.5%	🔻
kol-input-checkbox	32ms	30ms	+6.7%	🔻
kol-input-color	31ms	28ms	+10.7%	🔻
kol-input-date	35ms	34ms	+2.9%	➖
kol-input-email	35ms	32ms	+9.4%	🔻
kol-input-file	29ms	26ms	+11.5%	🔻
kol-input-number	30ms	29ms	+3.4%	➖
kol-input-password	32ms	31ms	+3.2%	➖
kol-input-radio	23ms	22ms	+4.5%	➖
kol-input-text	36ms	34ms	+5.9%	🔻
kol-link	43ms	40ms	+7.5%	🔻
kol-link-button	44ms	40ms	+10.0%	🔻
kol-link-group	8ms	7ms	+14.3%	🔻
kol-modal	6ms	6ms	0.0%	➖
kol-nav	10ms	9ms	+11.1%	🔻
kol-pagination	69ms	62ms	+11.3%	🔻
kol-popover-button	50ms	46ms	+8.7%	🔻
kol-progress	7ms	6ms	+16.7%	🔻
kol-quote	6ms	6ms	0.0%	➖
kol-select	35ms	31ms	+12.9%	🔻
kol-skip-nav	8ms	7ms	+14.3%	🔻
kol-split-button	53ms	49ms	+8.2%	🔻
kol-table-stateful	19ms	16ms	+18.8%	🔻
kol-table-stateless	16ms	14ms	+14.3%	🔻
kol-tabs	9ms	8ms	+12.5%	🔻
kol-textarea	33ms	28ms	+17.9%	🔻
kol-toolbar	7ms	6ms	+16.7%	🔻
kol-tree-item	47ms	44ms	+6.8%	🔻
kol-version	43ms	39ms	+10.3%	🔻