Fix rendering of font in ogimage

[SamyPesse]

This PR fixes incorrect font being loaded as were not caching based on the input text (sometimes loading a cyrilic font for a latin text, etc).
It improves it by introducing a built package @gitbook/fonts with our own mapping of fonts instead of doing HTTP requests to Google Fonts all the time.

[linear]

RND-7273 Random bold letters in preview images for docs sites

[changeset-bot]

🦋 Changeset detected

Latest commit: 9460e7a

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 2 packages

Name	Type
@gitbook/fonts	Minor
gitbook	Patch

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[github-actions]

Summary of the deployments:

Version 1

Version	URL	Status
Latest commit	https://b6b85c7e.gitbook-open.pages.dev	✅
PR	https://pr3299.gitbook-open.pages.dev	✅

Version 2

Version	URL	Status
Vercel	https://gitbook-v2-3j4o6sgwg-gitbook.vercel.app	✅
Cloudflare	https://a0b3a832-gitbook-open-v2-preview.gitbook.workers.dev	✅

Test content

Site	v1	2v	2c
GitBook	https://b6b85c7e.gitbook-open.pages.dev/gitbook.com/docs	https://gitbook-v2-3j4o6sgwg-gitbook.vercel.app/url/gitbook.com/docs	https://a0b3a832-gitbook-open-v2-preview.gitbook.workers.dev/url/gitbook.com/docs
E2E	https://b6b85c7e.gitbook-open.pages.dev/gitbook.gitbook.io/test-gitbook-open	https://gitbook-v2-3j4o6sgwg-gitbook.vercel.app/url/gitbook.gitbook.io/test-gitbook-open	https://a0b3a832-gitbook-open-v2-preview.gitbook.workers.dev/url/gitbook.gitbook.io/test-gitbook-open

[argos-ci]

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Build	Status	Details	Updated (UTC)
customers-v1 (Inspect)	✅ No changes detected	-	Jun 11, 2025, 11:27 AM
customers-v2 (Inspect)	👍 Changes approved	77 changed	Jun 11, 2025, 11:26 AM
default (Inspect)	✅ No changes detected	-	Jun 11, 2025, 11:29 AM
v2-cloudflare (Inspect)	✅ No changes detected	-	Jun 11, 2025, 11:27 AM
v2-vercel (Inspect)	✅ No changes detected	-	Jun 11, 2025, 11:29 AM