chore: regenerate bun.lock to match drivers peerDependencies layout

Commit 333a45c moved `@azure/identity` from `optionalDependencies` to
`peerDependencies` with `optional: true` in `packages/drivers/package.json`,
but the lockfile was not regenerated. That left CI under `--frozen-lockfile`
broken and made fresh installs silently diverge from the committed state.

Running `bun install` brings the lockfile in sync: `@azure/identity` is
recorded as an optional peer, and its transitive pins (`@azure/msal-browser`,
`@azure/msal-common`, `@azure/msal-node`) re-resolve to the versions required
by `tedious` and `snowflake-sdk`, matching the reachable runtime surface.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: suryaiyer95