feat: add en_GB localisations for form

[morenyang]

[中文版模板 / Chinese template]

🤔 This is a ...

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

🔗 Related issue link

#23369

💡 Background and solution

I think the validation messages for form in the UK could be the same as the US...

📝 Changelog

Language	Changelog
🇺🇸 English	add en_GB localisations for form
🇨🇳 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
• TypeScript definition is updated/provided or not needed
• Changelog is provided or not needed

[ant-design-bot]

[mjfwebb]

Yep they will be the same.

[hengkx]

/rebase

[yoyo837]

fork 出的不支持/rebase

[yoyo837]

Should import from en_US?

[codecov]

Codecov Report

Merging #24404 into master will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master   #24404   +/-   ##
=======================================
  Coverage   98.95%   98.95%           
=======================================
  Files         363      363           
  Lines        7260     7261    +1     
  Branches     1968     1968           
=======================================
+ Hits         7184     7185    +1     
  Misses         76       76           

Impacted Files	Coverage Δ
components/locale/en_GB.tsx	100.00% <100.00%> (ø)

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