chore: drop stale @azure/identity peer-dep entries from bun.lock

Commit 38cfb0e removed `@azure/identity` from the drivers package's
`peerDependencies` (tedious already bundles it), but the lockfile's
`packages/drivers` workspace section still carried the corresponding
`peerDependencies` and `optionalPeers` blocks. CI running
`bun install --frozen-lockfile` would fail on the drift.

Minimal edit — just removes the two stale blocks. No resolution changes
(`bun install --frozen-lockfile` passes with "no changes").

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

Author: suryaiyer95