docs: fix list grammar in CONTRIBUTING.md tooling section

[amir-rezaei]

Description

This PR fixes minor list grammar in CONTRIBUTING.md.

Details

Removed both when listing three items and added Oxford comma (supports Node.js, Web environments, and edge runtimes).

[Copilot]

Pull request overview

This PR makes a small grammar/style correction in CONTRIBUTING.md by removing an incorrect “both” when listing three items and adding an Oxford comma for clarity.

Changes:

• Adjusted the “Tooling” paragraph to correctly list three supported environments without “both”.
• Added an Oxford comma in the environment list for improved readability.

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✅ mshustov
❌ ferkans-amir
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[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.