deps: hold typescript at 6 until typescript-eslint supports 7

[yigitdot]

package.json pins typescript: "^6". Dependabot's monthly dev-dependencies group PR proposes ^7, and it cannot land: typescript-eslint does not support TypeScript 7 yet.

What breaks

With typescript@7.0.2 installed, pnpm lint dies before ESLint evaluates a single file:

typescript-eslint does not support TS 7.0.
Please see https://devblogs.microsoft.com/typescript/announcing-typescript-7-0/#running-side-by-side-with-typescript-6.0 to run typescript-eslint using the TS 6 API.

Oops! Something went wrong! :(
ESLint: 9.39.4
Error: typescript-eslint does not support TS 7.0.
    at Object.<anonymous> (node_modules/.pnpm/typescript-eslint@8.68.0_.../typescript-eslint/dist/index.js:52:11)
 ELIFECYCLE  Command failed with exit code 2.

It's a hard throw at module load in typescript-eslint, reached through eslint-config-next. That fails the website workflow's check job and, because the Pages build runs the same script, the Cloudflare Pages deployment too.

Upstream tracking

• typescript-eslint TS >=7.1 support: Enhancement: Use TS 7 (tsgo / typescript-go) for type information typescript-eslint/typescript-eslint#10940

Decision

Stay on TypeScript 6 for now. #231 is parked as a draft rather than closed so the other 11 bumps in that group stay reviewable.

This is the same shape as the eslint major hold already recorded in .github/dependabot.yml — a transitive peer that hasn't caught up yet.

Unblock criteria

1. typescript-eslint ships a release supporting TS >= 7.
2. eslint-config-next depends on a version of it that does.

Then: bump typescript to ^7, run pnpm lint, pnpm typecheck, pnpm test, pnpm build, and undraft/re-run #231 (or let Dependabot open a fresh group PR).

Optional, if the recurring PR noise is annoying

Add a version-update:semver-major ignore for typescript in .github/dependabot.yml, next to the existing eslint entry. Not done here — it would also silence the signal that the upgrade is ready.