refactor(utils): remove duplicated function

[OzakIOne]

Pre-flight checklist

• I have read the Contributing Guidelines on pull requests.
• If this is a code change: I have written unit tests and/or added dogfooding pages to fully verify the new behavior.
• If this is a new API or substantial change: the PR has an accompanying issue (closes #0000) and the maintainers have approved on my working plan.

Motivation

Avoid duplication of code

• should utils package import utils common and if not then how should addTrailingSlash should be defined ?
• merge only after fix(blog): apply trailing slash to blog feed #9920 which will cause a merge conflict

Test Plan

Deploy and jest ?

Test links

Deploy preview: https://deploy-preview-9949--docusaurus-2.netlify.app/

Related issues/PRs

[netlify]

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[github-actions]

⚡️ Lighthouse report for the deploy preview of this PR

URL	Performance	Accessibility	Best Practices	SEO	PWA	Report
/	🟠 62	🟢 98	🟢 96	🟢 100	🟠 88	Report
/docs/installation	🟠 66	🟢 96	🟢 100	🟢 100	🟠 88	Report
/docs/category/getting-started	🟠 76	🟢 100	🟢 100	🟢 90	🟠 88	Report
/blog	🟠 71	🟢 100	🟢 100	🟢 90	🟠 88	Report
/blog/preparing-your-site-for-docusaurus-v3	🟠 64	🟢 96	🟢 100	🟢 100	🟠 88	Report
/blog/tags/release	🟠 70	🟢 100	🟢 100	🟠 80	🟠 88	Report
/blog/tags	🟠 74	🟢 100	🟢 100	🟢 90	🟠 88	Report

[github-actions]

Size Change: +301 B (0%)

Total Size: 993 kB

Filename	Size	Change
website/build/assets/css/styles.********.css	114 kB	-64 B (0%)
website/build/assets/js/main.********.js	765 kB	+365 B (0%)

ℹ️ View Unchanged

Filename	Size
website/.docusaurus/globalData.json	75.4 kB
website/build/index.html	37.9 kB

_{compressed-size-action}

[OzakIOne]

Hmm need to investigate on this git merge main problem :(

Will be doing a new pr from main, won't have those merged commits problem 🙃