Release v2.1.11

This is a stable release suitable for use on Mainnet Beta.

What's Changed

• Bump version to v2.1.11 by @github-actions in #4541
• v2.1: Blockstore: Migrate ShredIndex type to more efficient data structure (backport of #3900) by @mergify in #4428
• v2.1: Scheduler Frequency Fixes (backport of #4545) by @mergify in #4577
• v2.1: Fix flaky test_transaction_result_does_not_affect_bankhash (backport of #3916) by @mergify in #4578
• v2.1: quic: disable send fairness (backport of #4586) by @mergify in #4590
• v2.1: tpu-client-next: return receiver in scheduler::run (backport of #4454) by @mergify in #4521
• v2.1: fix: use atomic to check if leader bank changed (backport of #4596) by @mergify in #4612

Full Changelog: v2.1.10...v2.1.11