chore: bump biome $schema to match pinned CLI 2.4.11

[EduardF1]

What and why

The repo pins @biomejs/biome to 2.4.11 (package.json ^2.4.11, resolved to 2.4.11 in the lockfile), but biome.jsonc still declares the 2.3.0 $schema. Running the pinned CLI on a clean checkout surfaces the drift:

> npx @biomejs/biome@2.4.11 check biome.jsonc
  i The configuration schema version does not match the CLI version 2.4.11
  i   Expected:  2.4.11
      Found:     2.3.0
  i Run the command biome migrate to migrate the configuration file.

This notice shows up for anyone running biome locally, and biome migrate is the intended way to clear it.

Changes

• Bump the $schema URL from 2.3.0 to 2.4.11 — only the schema line changes (+1/-1). Generated by Biome's own biome migrate --write; no rules, formatting, or ignore semantics are touched.

Validation

> npx @biomejs/biome@2.4.11 migrate --write
  - biome.jsonc: configuration successfully migrated.

# after: the schema-mismatch notice is gone
> npx @biomejs/biome@2.4.11 check biome.jsonc