fix: notify all key listeners on revalidation events

[pupuking723]

Fixes #2333.

This updates global focus/reconnect revalidation dispatch so every mounted listener for a cache key receives the event instead of only the first registered listener.

Previously, if multiple hooks shared a key and the first registered hook was paused via isPaused(), focus/reconnect revalidation stopped there and active consumers with the same key could not revalidate. Each listener already checks its own config before revalidating, and request deduping still prevents duplicate fetches for active consumers sharing the same key.

Verification:

• pnpm test -- test/use-swr-focus.test.tsx --runInBand
• pnpm types:check
• pnpm exec prettier --check src/_internal/utils/cache.ts test/use-swr-focus.test.tsx
• pnpm exec eslint src/_internal/utils/cache.ts test/use-swr-focus.test.tsx