[Bug]: "pnpm build" fails if playwright deps are not installed

[mikeharder]

Describe the bug

On Ubuntu 24, command pnpm build fails if the playwright dependencies are not installed. The CONTRIBUTING.md doc indicates the playwright dependency is optional.

https://github.com/microsoft/typespec/blob/main/CONTRIBUTING.md#repo-setup

website build: 18:16:27 [build] Building static entrypoints...
website build: browserType.launch:
website build: ╔══════════════════════════════════════════════════════╗
website build: ║ Host system is missing dependencies to run browsers. ║
website build: ║ Please install them with the following command:      ║
website build: ║                                                      ║
website build: ║     sudo pnpm exec playwright install-deps           ║
website build: ║                                                      ║
website build: ║ Alternatively, use apt:                              ║
website build: ║     sudo apt-get install libatk1.0-0t64\             ║
website build: ║         libatk-bridge2.0-0t64\                       ║
website build: ║         libatspi2.0-0t64\                            ║
website build: ║         libxcomposite1\                              ║
website build: ║         libxdamage1\                                 ║
website build: ║         libxfixes3\                                  ║
website build: ║         libxrandr2\                                  ║
website build: ║         libgbm1                                      ║
website build: ║                                                      ║
website build: ║ <3 Playwright Team                                   ║
website build: ╚══════════════════════════════════════════════════════╝
website build:   

Reproduction

Run pnpm build on Ubuntu 24 without playwright

Checklist

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• Check that there isn't already an issue that request the same bug to avoid creating a duplicate.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion.
• The provided reproduction is a minimal reproducible example of the bug.