docs: fix icon demo exception when prerendering

[ElderJames]

🤔 This is a ...

• New feature
• Bug fix
• Site / documentation update
• Demo update
• Component style update
• Bundle size optimization
• Performance optimization
• Refactoring
• Code style optimization
• Test Case
• Branch merge
• Other (about what?)

🔗 Related issue link

💡 Background and solution

📝 Changelog

Language	Changelog
🇺🇸 English
🇨🇳 Chinese

☑️ Self Check before Merge

⚠️ Please check all items below before review. ⚠️

• Doc is updated/provided or not needed
• Demo is updated/provided or not needed
• Changelog is provided or not needed

[github-actions]

[codecov]

Codecov Report

Merging #2527 (2c8fd5c) into master (a590d93) will increase coverage by 1.94%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2527      +/-   ##
==========================================
+ Coverage   27.71%   29.66%   +1.94%     
==========================================
  Files         497      520      +23     
  Lines       33433    25623    -7810     
  Branches        0      250     +250     
==========================================
- Hits         9265     7600    -1665     
+ Misses      24168    17983    -6185     
- Partials        0       40      +40     

Impacted Files	Coverage Δ
components/core/Helpers/MemberPath/PathNode.cs	46.15% <0.00%> (-8.85%)	⬇️
components/core/Reflection/TypeDefined.cs	77.77% <0.00%> (-7.94%)	⬇️
components/input/InputGroup.razor.cs	87.50% <0.00%> (-6.95%)	⬇️
...ponents/date-picker/types/DatePickerPlaceholder.cs	22.72% <0.00%> (-4.20%)	⬇️
...ponents/core/Component/Overlay/type/TriggerType.cs	81.25% <0.00%> (-2.97%)	⬇️
components/core/Helpers/DateHelper.cs	80.00% <0.00%> (-2.71%)	⬇️
...onents/date-picker/internal/DatePickerHeader.razor	43.90% <0.00%> (-2.48%)	⬇️
components/menu/SubMenu.razor	63.93% <0.00%> (-2.30%)	⬇️
components/timeline/Timeline.razor.cs	63.21% <0.00%> (-2.24%)	⬇️
components/core/Helpers/THelper.cs	36.00% <0.00%> (-1.78%)	⬇️
... and 424 more

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